This is likely the point of the rule: to discourage otherwise-high-quality comments that might inspire a wave of crappy ones.
Yes, and I like it (a lot). Especially now that the comments are hidden. When the comments were still visible it was more necessary to reply (so that errors aren’t accepted without correction). Now the (presumably, more often than not) bad replies don’t require high-quality refutation because they are invisible to those who don’t seek them out. The penalty to comment replies has very little downside.
Yes, and I like it (a lot). Especially now that the comments are hidden. When the comments were still visible it was more necessary to reply (so that errors aren’t accepted without correction). Now the (presumably, more often than not) bad replies don’t require high-quality refutation because they are invisible to those who don’t seek them out. The penalty to comment replies has very little downside.