I'd imagine that those two are not a mutually exclusive set.

Besides, if a troll makes a reasonable point, does it matter that he was actually trolling? Truthfully it's snark that bothers me most - I can deal with someone being playful or contrary for the sake of it, but too much snark just triggers a very primal part of my brain that makes we want to start cracking skulls, and that's not very conducive to continuing the discussion.