I have always cleared them every now and than.
I don't feel like clearing them too often as people are worried I censor. Which I clearly never did but its mainly cause they have no idea what censorship is and they confuse their rant comments with valuable feedback.
But yeah, I see now there are comments from before patch 1.60 and that does not really make sense. I will clear the comments to make sure all comments are actually from the post 1.60 release.
I hope that satisfies your wish (even its only a bit)