Isn't it funny how two people can listen to the same broadcaster and hear totally different things.
I dislike JH's style. His 'tearing into' is counterproductive; it doesn't elucidate the truth, it just makes interviewees play games in return. JH doesn't care about the topic in hand - he is far more interested in winning the fight, in beating down his opponent, in being the Alpha Male.
He has to do warm & twinkly every now and then to give a contrast. A bit of yang to go with the yin. Same as Eddie Mair - I don't like it when he does 'cuddly' to a member of the public but 'rottweiler' to a politician. It is blatantly currying favour along the lines of "I'm nice to ordinary people, like you dear listener, but horrible to Them, the scumbags who are from a different race entirely."
I know I am probably unique, or weird, but I just love John Humphrys. I think he is a brilliant interviewer and cheer when he tears into some lying scrumbag politician/banker/tax-avoider. But today he was talking to a female rocket scientist about dark matter or something, and she was giggling, flirting even. I have noticed this before. Clever women seem to come over all soppy when they talk to him about some baffling concept. And he responds with a lovely, warm, twinkly manner. So I guess clever women like clever men and can see the appeal of a superior mind. Explains why I love him .