I honestly think they don't care what the passengers think. When flex dining was introduced in June 2018 there was a huge outcry,petitions,writing to influential people,etc and what was the result? Flex dining on every Eastern train in October 2019. This was BEFORE the pandemic.
The only reason traditional dining is returning on the Western trains is the overwhelming negativity and Amtrak can rationalize these are two night trains and the flex dining remains on the one over night trains. If nobody complained,I am certain flex dining would have continued.
As far as the SSL cars I have a feeling they will never return on the TE and CL no matter what we do...and now we are dealing with sky high sleeper prices that most people can't afford or think they aren't worth the high price,considering all the alternatives.
I have been a faithful Amtrak rider for over 30 years taking a long cross country train-cation every year,but I will not pay $900 for a roomette between Chicago and LA. Obviously,some people will and that's who Amtrak is catering to.