The room attendant knew they requested dinner delivered so she would not have to talk between cars, but told them she could not do 9pm they'd asked for at check in as she'd be setting up beds by then. They agreed her suggestion of 8:30 would be fine. By 9 and no dinner they paged her and caught her in the hall a bit later. She said the paging system was down. She said the kitchen told her they could not have the dinners ready for another 20 minutes. Finally at 9:45 (remember, she insisted she'd need to bring at 8:30) she delivered them and as you'd guess they were stone cold.
The SA has many duties, and many passengers to attend to. If by 9pm (kind of late for a dinner IMHO), the SA normal duties involve converting all the roomettes and bedrooms to their night-time configuration, I can easily see it being reasonable that the SA would not want to take on something additional like delivering a late dinner.
The fact that the SA was accommodating (bending her hectic schedule) when the dining car was running late, and bringing the food at 9:45, I see as a plus. I don't think it was appropriate for you all to ridicule the SA for what should be a pat-on-the-back. What did you rather want the SA to do? Tell you that the since the diner car is running late (past 9pm), you're not going to get your meal at all now?
Sorry that your meal was "stone cold". I guess you should have sent it back to the dining car and hope that someone there, could fix it.