Some do, actually. I won't disagree with the sentiment that there isn't enough activity there, but NPCs do actually go there. Hell, Clint starts not opening on Fridays just to go to the CC once it is rebuilt.
Yes I agree more should happen in the community center! I suggested that it would be neat for a cooking festival to unlock after completing it as an extra reward (vs Jodi/Caroline/Gus), and I think it would be cool if many Villagers who don't go to the Saloon on Friday evenings could go to hang out there Saturday or Sunday as another simple way of being able to mass gift harder to find NPCs :)
Absolutely! I'd be happy to see any event in the community center honestly- if you choose the 'talk it out' option in the cutscene, Pierre has a very touching speech about how the community needs to become stronger again and then...nothing changes at all haha. Any new community center/spa event, or weekly change in some character schedules would feel more fitting I think.
Edit: I know there are some changes in schedules like Clint's, but nothing for groups of characters