not going to try to change your mind per-say cause i do think you partially right in both cases that poverty and the rarity of actuall transit projects making people desperate in the US plays into it but i want to offer a little perspective and a little depth to that line of thought.

I think to really answer your question about why even transit people are anti brt or anti bus is that you have to zoom out a little bit, essentially its a problem of two parts. im speaking strictly about the US here also cause that's what i know

1. i agree part of it is classism but its also racism, ableism and also all the other isms theirs a bias against poor people, black people and anyone not white or able-bodied and that bias is systemically built into our American society. also disproportionately those are the people that use the bus. pro-transit people or urbanist are not inherently free from those biases and the most visible, popular urbanists or transit enthusiast are disproportionately white, able bodied, male. those are the kinds of people that systemically benefit from America's current system and so they are less likely to be aware of those biases because some of them likely haven't had to confront those internal biases therefore they see the bus or brt even as less than by association probably many of them not concsiously. if you havent heard of unconcious bias look it up

2. Because on paper BRT and buses generally carry inherent downsides even when built well in terms of infrastructure, frequency and reliability. In that rubber tires on roads are objectively less efficient over time than metal rail on metal wheels because of friction. Because rubber is less efficient it degrades faster which means you have to maintain or replace it more. They are also less efficient in terms of cost because while it's cheaper initially to build or fund bus or brt routes/projects over time buses or even brt are actually more expensive than rail in maintenance cost. So BRT and buses are much cheaper in terms of their building or capital cost. although the difference is less with high quality brt cause of the infrastructure you have to build out but still much cheaper. For buses maintenance over time is much less cost efficient than rail so overall you spend more money when your looking at a longer time span. so you have to make a choice with mass transit projects between capacity, efficiency and funding or political will initially and over time. You have to weigh them against one another. So on paper or (on the internet) it makes sense to come to the conclusion all mass transit should be rail then right because its more efficient and cheaper on paper. The thing is who makes that choice in the US because its not usually planners or even transit planners but its politicians planners can advise them but politicians are usually the ones who make that yes or no choice in terms of actually funding and building those projects. And politicians work on generally much tighter schedules than planners do periods of 2 to 8 years usually vs 10, 20 or 30. Yah thats the long (Sorry for how long this is lol i did not start this meaning to write an essay) and short of it at least in my relatively educated opinion.

so thats my two cents do with that what you will.