I think `dang recently mentioned* that he's found the majority of downvoted and greyed out comments to be noncontributory. If that's the case, then there's little reason for them to be read.
The goal, I think, was to reduce noise for the majority of users. If someone really wants to read a grayed out comment, they are entitled to do.
Seems to work just fine.
Would it not be better to allow people to make up their own minds about it than to make that choice more difficult?