Nope. I think that being able to completely eliminate certain absolutely insufferable individuals from your game is a good feature. They only have themselves to thank for it. HOWEVER, it is also one that's wide open to shenanigans, but that's the case with every feature, however well-intentioned, throughout the history of mankind. We never disappoint in our ability, as a species, to take something potentially brilliant and figure out how we can abuse it.
That being said, I would like to emphasize that it is, indeed, a sledgehammer rather than a tweezer, and as such should be used extremely sparingly. Which is why my block list is empty and shall most likely remain so forever. Somebody would really have to go out of their way to get me to use it and, on those exceedingly rare occasions that I have not encountered yet, I'm even having trouble imagining just how bad it would have to be, I wouldn't hesitate to use it. But that would have to rise to the level of stalkerish, obsessive behavior suggestive of a highly emotionally unstable individual, and I haven't encountered any of those yet. They are, after all, exceedingly rare, and thank Bob for that.