To be fair, a similar poll of philosophers working in the Continental traditions would probably yield something similar but this time aimed at the Analytical tradition. It will be interesting to read the justifications from those who voted for Heidegger (although I suspect that most of them will not respond since they probably never actually read Heidegger).
I don't know about that. The continental vs analytic split is very much an invention of the Anglo-American academy. If I go to my local (USA) bookstore, the shelves are filled with the authors on Leiter's list, plus Plato and Aristotle. There are no books by analytical philosophers on the shelves. If it wasn't for the corrupt educational system that permits professors to require that students buy their textbooks, no one would publish analytic philosophy because there's no audience for it. It's the same when I travel abroad, there's the core of Western philosophy, and there's an analytic specialization. It's only in the Anglo-American universities that one finds this upside down world where they pretend analytic philosophy is all that matters and the Western tradition is seen as pernicious - as in: if you mention Hegel, the McCarthyists will end your career.