As far as I know, we don’t have user based karma here. Only posts and comments get a score. But we really should make sure that the community does not get over-run with a specific type of post. Unless the community is for that specific purpose, of course.
But I can imagine that not every instance would like to host a “share your Kickstarter project” community, as those posts will also show up for the users that like to read all local posts. Here on Lemmy.world that feed would already be a full of stuff you aren’t interested in though, but that’s my opinion and I also never used r/all or any of the other extremely broad subreddits.