It does make it hard to tell at a glance who is who, at least if I'm reading it on my phone and the icons are tiny, but otherwise I am 100% for it. I have a lot of coworkers/former coworkers and such friended on my FB and as I'm not out at work (as queer (open to being out) or trans (stealth 4eva)), it was really heartening to see so many people change their icons. (I didn't change mine (mostly lazy) but I "liked" every rainbow icon that came up on my feed.)