The only time I'm criticizing other cyclists to their face is if they're significantly endangering themselves, me and/or other people--passing kids too close, for example or randomly popping into my lane from the other side. I also used to tell people to turn off their damn bright strobes on the bike path (that really is a safety issue), but that fad appears to have come to an end around here. I really haven't been blinded by one in at least a year and a half.
And platform pedals rule!