Debate aversion

Greg Mankiw notes that academics often don't like debate formats. As someone who loves debates, whether as participant or observer, I find such aversion a bit puzzling (why wouldn't you want to test and perhaps sharpen your ideas?) but I also think it's found well beyond academia. Some business conferences I've been to would have been enlivened had people on the panel aired their disagreements, rather than ignored them or hinted at them obliquely. In particular, I suspect if more financial conferences had featured debates about the newest incomprehensible instruments, the crisis would not have been quite as much of a surprise.