I don't have the data to support this but I would imagine that there are relatively few people that redeem for loophole type long distance sleeper awards and few that earn status simply by taking point runs on the keystones. If either found there way into the mainstream, AGR and Amtrak would be forced to take action.
If one books 20 low bucket BOS-NYP BC Acela trips at $93 each, they would earn S+ status with spending $1860
a WAS-NYP customer booking 20 low bucket BC Acela trips at $133 each, they would earn S+ status with spending $2660
Both customers are probably equally desired but one is spending $800 more for the same perks.
There are probably quite a few in each market that spend more as well because they don't always get low bucket.
Prior to the 100 point minimum per ticket rule, anyone outside of the NEC would be stuck spending a minimum of $5000 per year to get any S+ perks which is nearly double what even a WAS-NYP Acela rider would. Though unlikely, anyone that did spend $5000 per year on Amtrak travel outside the NEC would also have to be considered a valuable customer from strictly a revenue sense.
I would imagine that when Amtrak instituted the 100 point minimum rule it was to say to everyone else outside the NEC that you matter too, even if rewarding them was never a primary objective of AGR.
Of course, the 100 point minimum rule now makes it possible for people to earn status by spending far less than $5000 or even $1860 but those that do are probably in the minority and do little to water down status for everyone else.
I knew an elderly woman and her daughter that at times would commute on the EB from La Crosse to Tomah and back 2-3 times per week to visit their elderly husband/father at the VA hospital in Tomah. Even at low bucket senior/disabled fares, a run like that works out to be around $10 each way. There were even times when the conductor, knowing the purpose of their visit, would "forget" to pull her ticket so she could visit her husband later that week and still make ends meet. When they started making the trips, I don't think either of them were registered for AGR anyway but were still spending a couple thousand dollars over the course of a year. After they registered, both earned S+ status but riding La Crosse to Tomah and back was their only connection to Amtrak. They redeemed points for free coach travel from La Crosse to Tomah and never had a chance to use any upgrade coupons or sit in the Metro Lounge or CAs.
From Amtrak's perspective, they were probably great customers from a revenue standpoint and the benefits they did gleen from their status--free $10 coach redemptions--did little to hurt the bottom line.
Now conceivably, you could have a few enterprising people that ride keystones back and forth, earn status, redeem expensive First Class Acela upgrades, visit the CAs on a regular basis when not even riding and take space away from paying First Class customers. However, few people probably operate like this.
You could also have that one or two people that pay $2 low bucket from Summit, IL to Chicago, accumulate status and redeem their points on a costly sleeper award on the EB during peak summer months. When I did this run once, I was the only person. The same is also true when I'll ride from CHI to Glenview and back on the Hiawatha.
During National Train Day last year, I did the CHI-Glenview run to earn quadruple points and was surprised that day to see another person waiting on the platform to make the same run. When I looked closer, I realized it was a fellow AUer and two of his friends. It was nice that day to earn 400 points for an $8 ticket, yet, as railfans I know we were still in the minority. Every other person that day was still taking metra and life was normal. I doubt Amtrak's bottom line was affected that day.
Any program that is designed to advertise a company's brand and bring people in the door can cause some knowledgeable people to take things to the extreem.
If everyone just bought the loss leaders at the grocery store each week or that deeply discounted DVD each Tuesday and left, without buying anything else, policies would change and the bottom line would be affected.
By having the 100 point minimum rule, I've probably taken a few trips to Chicago for fun that I may not have taken otherwise, but I've also paid cash for sleepers that may have otherwise gone unsold. I also took the CL from CHI to WAS to CHI so I could ride the Acela to and from the Boston Gathering when I could've paid less for a regional. By having S+ status, my primary perk is getting to sit in the CHI Metro Lounge and consume free pretzles and fountain soda, have easier access to red caps and a comfortable place to wait between trains.
It's a valuable benefit for me, but I don't think it's probably costing Amtrak that much in the long run. Now, if the number of S+ people in the midwest became so large that it became impossible for sleeper passengers to wait there, the pretzles ran out and the soda fountain ran dry, that would cause a problem. The 100 point minimum may go away or the # of rail points needed to qualify would go up. Yet, I know I am in the minority simply because some of the agents would still look at my AGR card funny when I would show it to gain entrance.
Recently, I redeemed an AGR free companion coupon to take my brother and his wife to CHI. Both had never been on Amtrak or to CHI, yet both are considering repeating it in the future so that AGR coupon may have actually brought new customers to Amtrak.
Even when AGR instituted the rule that only 4 segments per day would qualify under the 100 point rule, it probably had little affect on all but a few ardent rail fans. As an aside, it affected me but only because I took a trip on Thanksgiivng to visit relatives and that segment had posted on the wrong day to begin with. After calling AGR, they posted it on the correct day and I got the points.
Finally, being that AGR was designed to reward those on the NEC riding the Acela, I have to wonder what they were thinking. It is $93 to ride from BOs to NYP, and $133 to ride from NYP to WAS at low bucket. Now, from what I've been told, the price differential is related to Amtrak's ability to compete in those markets. Amtrak has a higher market share in NYP-WAS and can charge more based on what people will pay. They have a smaller market share from BOS-NYP and more competition and charge less.
What few people may realize is that riding Acela all the way from BOS-WAS only costs $149. In comparison, that seems absurdly cheap. Add to that a free upgrade coupon and the ability to consume two meals and double the alcohol and I wonder why Amtrak hasn't done more to stop what could be a disaster in the making. Imagine if Amtrak suddenly captured 70-80% of that elusive BOS-WAS market. Acelas would zoom full speed into Penn Station and no one would get off. NY-WAS passengers (in Amtrak's highest market share since the metroliner days) would be left on the platform and NYP-WAS market share and the bottom line would probably be dramatically affected.
Somehow, I doubt Amtrak is worried about this scenario. I've done it 4 times and each time seen the train clear completly with the exception of myself and maybe 1-2 others, only to see a whole new set of passengers get on in their place. The idea that a bunch of business professionals are suddenly going to avoid flying and instead spend 6 1/2 hours riding a train would not be typical for most of those people.
I'm sure AGR realizes that some customers will engage in behaviors that the majority of its customers would not and as long as they are in the minority, I doubt Amtrak or AGR is too concerned.