Good question, Journeyman.
I think every person--especially men--want/need reinforcement and praise that we are doing a good job. If I build a good bridge, by golly, I want someone to say "Damn, that's a good bridge!" If I go against the crowd and predict a huge upset, I want someone to say, "Damn, El, nice call on that upset." It's human nature to desire appreciation for good work.
So, naturally, the posters who win a fair amount of picks desire a fair amount of ego stroking. As we get older, we get better at just being happy to help others succeed and don't need all the credit ourselves.
But since gamblers as a group are risk-takers and, let's face it, at least a little greedy, we want positive reinforcement for our good picks. It's just too bad that some of us have to be dicks about it instead of just admitting that we'd like a little love for our good work. JMHO