I think a common perception is that if someone is good at a sport and wins the competitions they enter that they would be happy about that, Brad just seems to not be. You want to be elated for him when he wins but when he seems down about it it's hard to empathise with him. It rubs some people the wrong way.
I just think he is trying hard to be very honest in his interviews, he love riding and training for a goal, once he's achieved that goal it's over and on to whatever next.
I think if you read the articles the thing that really pxssed him off about the whole thing was the constant questions about the LA thing - more attention on that rather than what he had achieved in Paris and London -plus on top of that he hardly had a stella year immediately after that.
Personally I like his honesty - and as he is probably ranks among the two or three most successful male British cyclists of all time he deserves plenty of slack.