I started by disagreeing with you but after reading your comment about 10 times I think I agree completely.
As long as I'm notified that they are there and I can un-hide them and take a look myself.
I think it could be helpful if the author of the post could grey out, NOT hide or block replies.
I just think that I should have more control over what is replied in my post. I would not want to see 100 comments all full of foul language, I don't think anyone would like to see that. So a greyed out post that if visitors want to see why I have someone muted they would be able to make a determination in their mind that it was for possibly for cause.
Making a comment cost nothing, downvoting it to a point it is not viewable can take a lot of steem power.