Also here via vriddy, and wanted to add that many things I thought of seeing after reading the post are things you've mentioned here, such as changes in the number of people involved, the mainstreaming (and also the style and focus of platforms people first engaged with) and the influence of other things happening online which bleed into fandom spaces.

If anything, the move to privacy controls seems a return to me of what LJ had long offered and which DW has improved upon. It's just that a lot of fandom sees this as "new" and haven't learned anything from history.

I'd agree about any sort of tip jar function, which does not seem that different to me from people sponsoring other people's paid accounts, offering them gifts and so on which went on quite a bit in the LJ days. A forced exchange is a different thing.

However my experience with Buffy and SPN are reversed. There was certainly a fair amount of response in both, but I still remember the shock I felt at seeing pages of comments to a number of fics being posted when I first joined the fandom in 2006. Part of it was likely the decline in activity in the Buffyverse compared to the surging activity in SPN. But I found the same was true for my own meta posts as with fics I read.

All of which is to say that there can be such a lot of different experiences even at the same times in the same fandoms.