Seeing "User Deactivated" on a comment/post always bothered me... my thinking is that even if they aren't around any more, they still made that comment, and that username should still be linked to the comment.
I think it's some combination of "own your shit" and "good content can also be from people who aren't here any more".
Today I noticed a change where instead of "User Deactivated", it displayed the username with a line through the name (strikethrough).
The indication is still clear, and I like it: The account no longer exists, but this is what they had to say.
Yay for this feature!