I see your point, but wouldn't that be nice to let community admins determine what makes sense for their community? I think it could make a difference on where a community is in it's life cycle, or who it's target users are.
A newer community may need help to drive additional engagement. Or in a very established community, sometimes the same users writing all the time can get stagnant, and the push for new topics can help rejuvenate things.
Also, less Web savvy users may need a little action design to get them to post / signup.
BTW, when thinking about taking action on the heart icon for new users, would be interesting to think about what that means about email confirmation. Can I start liking topics during my first logged-in session before going to my email to activate my membership?
Oh, this may be slightly off topic, but somewhat relevant to the discussion. If I login with Facebook, am I still required to confirm my email? AFAIK, if you haven't already confirmed your email with FB, then you won't be able to login to other sites.