I would never use it in this functionality because, no matter how I feel about someone, I want to be able to view their input if there is one (across the site, at least).[1] I advocate for a collapse-the-comments and turn-off-notifications approach as opposed to total invisibility. That way if you want to see it it's there, but you have to go digging for it and you realize what you're getting into. If it's a user you just absolutely can't stand/can't interact with, you don't expand the comments and go looking for a fight.

There have been users I've really disliked 95% of the time here, but 1-2% of the time, I have agreed with their comments and thought they were right. I don't want to lose the ability to occasionally agree even if I mostly detest a person.

[1] Yes, this may seem ironic as I've used "mute" and it removes a user from my posts - but then it's clear cut; there's nothing there not to see. In addition, it doesn't apply site-wide, but only to my posts, which I think makes a difference as with mute as it currently is I can still see interactions occurring outside of my posts.