I seldom check who follows me, but focus on who comments on my posts. Sometimes, when I have little mental energy, I only get to answer the comments on my own posts, but I prefer to comment on all the quality posts I can - and to do that effectively I have to have a feed that is reasonably weeded out.
I do not revenge-unfollow - it really does not mean much to me and as I seldom notice, there is no harm in unfollowing me.
'revenge-unfollow', now there's a term for us. Neither do I really.. though in the example of Steemain (1) I did unfollow but not for this reason.
A lot of varied responses and good debate :)