You are right that the decline is social, but it's not because "they" want anything. RSS was never a technology that managed to catch on outside the uber-geek crowd. I use "uber-geek" intentionally because it seems to me that most tech-savvy people I know don't use feed readers (in their browsers or otherwise).
I think you're conflating 2 things: RSS as format read by people and RSS as a format read by machine. Don't let the lack of popularity of the former sway your opinion of the latter.
Having to write custom code for each service you're interested in sucks compared to adding some RSS endpoints into an array.
