The problem is that the smaller, curious topics—like puffins—tend to get sucked into the nearest black hole, i.e. the nearest large generic controversy. If we allow this, then the site will consist of the same few comments about the same few topics over and over. That's bad for intellectual curiosity. It also causes the site to burst into flames—not good for curiosity either.

I called this 'dumb' above because you can reliably see such threads deteriorate as you read down and to the right.