The reason I dislike this, is that besides obviously racist or otherwise inappropriate comments, there are regularly normal seeming comments that are dead. Now, there may be reasons for this I am just not privy to, but I feel it hinders discussion when some opinions that don't seem problematic are just silenced like this.
[Edit]: And rereading my own comment, I think I want to clarify that I am not talking about free speech issues or political discussions here, but I regularly encounter factual seeming or explanatory comments in technical discussions that are dead and it just baffles me.
Usually when I see a perfectly good, but dead, comment I check out the user's history. I usually see one of two situations here:
1. It's clear that they have a pattern of making nasty, off-topic, often vulgar comments. I'll still vouch for their good comments, but at least I can understand why they were dead to begin with.
2. If their history is of mostly normal comments except one bad joke at the start of their posting history that got them hell banned, then I'll vouch for them and let them know what's happened.
Moderation is guesswork, and even if we guess 99% accurately about which accounts to ban in the early stage—a necessary thing to do, because otherwise the site would be overrun with spammers and trolls—that still leaves quite a few false positives who later turn out to be neither spammers nor trolls.