At every station, they do not always open every door, so they try to seat people by destination whenever possible.
Maybe this time that's simply not possible. Maybe this time they'll simply open a
different door and put the family in
another car. ... If not then why should I be forced to let them into ... the single paid seat next to me?
Many stops are just long enough to board passengers (like under 1 minute). Many times, by the time I put my luggage in the rack and get upstairs, the train is already moving. So the family gets upstairs and then finds that the only seats are on opposite ends of the car, and that
YOU do not want to move - are they supposed to stop the train, call dispatch to get authorization to back up, have the Conductor position himself or herself at the back door, and then back up to the station - just so they can open another door?
Remember that you did not purchase 2 seats next to each other (unless you
SPECIFICALLY requested seats #1 and #2), which Amtrak does not do! You only reserved 2 seats on that certain train, but there is nothing that says they must be together!
Why should 1 person be allowed to take 2 seats next to other at the expense of a family that wants to sit together?
Part of traveling on Amtrak is meeting and taking to other people! I supposed you are one that also demands to be seated in the Dining Car booth alone - restricting 3 other passengers from having a meal?