Punks have gotten universal on all chains, these have some uniqueness to it afaik. It's kind of like forks I assume.

For everything else, dlive fucked off way before sun and ended up in sun's pocket anyway after blowing their load on pewdiepie. Steemchiller wasn't supported as steemworld was closed sourced, doesn't happen with all closed sourced projects (see peakd) but majority won't get DHF support so he decided to stick with steem, probably doing well there as the only competetend developer, though I doubt he's developed anything since.

As far as caring about the population, I can tell you hands on curation has never been better, even on the current linear curve where selling votes would technically be possible the community has learned that that's not the way and curation is happening and being spread out wide, take a look at trending daily how many new accounts end up there. I wouldn't say everyone's in it just for their own ROI, but if you look at Steem you may see what that actually looks like and a broken curation system without a care.