They used to, but the fun or tasteful ones are quite amusing so I don't mind them so much anymore. Some are still quite rubbish truth be told...the beauty of the still is that it's the pictorial equivalent to a single sentence; a small snapshot to separate ourselves, to give us each a unique "signature" or personality of sorts (for lack of a better term. You all know what I mean).
I think the one that convinced me is someone on this forum whose avatar is Sheldon from TBBT in the ball pond, popping up in a spray of colour. Even though there's no sound, I can hear the Bazinga. Whoever you are, it's bloody brilliant
Also, I'm sure I saw this [http://www.youtube.com/watch?v=0fc8j_CTuYM&feature=player_detailpage#t=54s] in someone's profile, cracks me up every time.