Personally, I don't have a very sparkling personality, and I'm not good at small talk. At times, I've tried to initiate a conversation in the diner unsuccessfully. At other times, others at the table have struck up a lively conversation, and my attempts to join in have been mostly ignored. So I just retreat.
So why would I want to eat in the diner rather than my room?
- I want my meal hot & fresh (or dessert cold & fresh)
- I may want condiments which the SCA would not bring
- I may want a refill on my drink
- I may want a cup of coffee with my dessert
- I may want to enjoy the view out both sides of the train
- I enjoy the ambience and activity in the diner
- I don't want the lingering aroma of my meal in my room
- The fold-out tables are small and often unsteady
IMO, I have as much right to eat in the diner as anyone else in a sleeper, even if I'm not socially outgoing or a splendid conversationalist, and even if I choose to focus on my tablet.