Personally, I rate the guy as a manager.
I also think that people are unable to separate his mind games in the press from a personal viewpoint. He is by no means an idiot, and the two times that I've met him (once at a funeral/wake, once in passing), he seemed both extremely nice/polite and extremely knowledgeable about the game. To be honest, his ability to manage a group of young stroppy footballers to success is immediately apparent just when you meet him. He's a deep thinker, but carries himself in a strange way that seems to exude dignified confidence and respect. He's hard to describe.
I sing the song because it's a bit of banter really. People need to start learning that singing a specific football song doesn't mean that you hold that true opinion.
I don't particularly "hate" the man, because I don't know him. His words in the media are designed to get people riled up as a way of deflecting from his team and it works EVERY SINGLE TIME. Sometimes, he says things as a way of getting the opposite team fired up thus make them lose their concentration on the game. This is a hugely important aspect of modern management, and Mourinho, AVB, Mancini, Wenger, Guardiola and all the other top guys do it too.
This was always Benitez's big failings, he could never work out that it's all just a game, and he took everything to heart, costing him the title on numerous occasions.