As a gradstudent wading (or pulled, hard to tell some days) deeper into the academic current, I've begun to encounter a species of academician, who, for reasons at which I can only speculate, seems to cease to feel the need to respond to critics, or support their views with anything approaching evidence or a reasoned argument. Not long ago I watched a full professor invited to a panel following a guest lecturer arguing for a reconceptualisation of an established idea show up late, miss the lecture, and then proceed to declare that (1) he didn't need to hear it anyway because he'd heard it all before and (2) it was bunk, and (3) besides, the guest wasn't a real _____ist, because he wasn't employed in a ____ology department. It was made worse because the lecturer had another engagement and left before the late one arrived. [The guest lecturer in question, another full prof, actually received his PhD in the same thing, from the same department, at the same school as his challenger but was employed in a multidisciplinary department elsewhere. Yeah, he stepped in it.]
It's painful for us gradstudents to witness something like the above, or the exchange Dr Dawg has posted here between accomplished Professors Amir Attaran and Margaret Somerville, where at least one party seems uninterested in debate over their ideas or arguing in good faith. We might wonder about the truth of the rigorous intellectual meritocracy that we're told maintains the quality of research and ideas, when we see someone like Somerville, with the FRSC postnomial, at first dismiss and then waffle on directly addressing specific critiques of her published claims, and insult her critic. We might start to wonder how she and others earned their stripes.
Arrogance from academics? Sure, it's annoying at times and mightn't incline you to invite them for drinks or seek them out as a supervisor, but it's usually tolerable when it's coupled with a sound engagement of the subject matter. When they stop doing latter, and keep up the former, they also stop behaving like academics and start acting like politicians. In my personal anecdote and the Attaran-Somerville exhange, the individuals were unwilling to hear criticisms and boorishly dismissed their 'opposition' with dodges and ad hominem attacks. It's a lot like watching the assortment of blinkered hacks and shills in Question Period, or arguing with a Blogging Tory.
The unfortunate bit is that tenured academics who feel they are somehow beyond criticism are even harder to dislodge than like minded politicians.