My instance requires that users say a little about why they want to join. Works just fine.
If someone isn't willing to introduce themselves, why would they even want to register? If they just want to lurk, they can do so anonymously.
EDIT I just noticed we're from the same instance lol, so you definitely know what I'm talking about ๐
As a forum user I agree, but would like to add that many forums do have a kind of "demerit point" system for incivility. Where racking up enough points gets you temporarily muted or banned.