Ineffective? I disagree. Walker/Molyneaux obviously have a longer relationship and know each other. Walker, being a journalist, prepared for the interview and knew how to rile Molyneaux up to get him emotional. This in turn leads into a slightly heated interview with some brutal honesty on both sides, with is pretty refreshing in an indstury full of PR-fluff.
The one really making Molyneaux look bad in that interview is Molyneux himself. He is not prepared for the interview, seemingly has no clue about the responsibilties he caries as head of his projects and seems unfit to be at the front of anything involving time management, finance as well as the organisation and structuring of his personal. I think some people are more irritated at Peter but project that onto John, because he is seen as the aggressor in this context, the one initiating the uncomfortable situation, when he is in truth only using very basic concepts of interview technique, that every public figurehead of bigger companies in the world should be trained to cope with, to get to the points he wants to present.
I don't really like the interview style myself either. The pathological liar question, while not really disrespectful, is a pretty tricky opening for one. A liar wouldn't say yes, a normal person would also say no, but someone in the position of Molyneux should at least not get defensive and somehow cool down the situation at the beginning. He totally let Walker take over and drove himself into a corner with his reactions and constant victimisation, which, with a bit of self reflection, should be obvious to rile up people who have gotten burned by his overpromising in the past.