I haven't left philosophy because everyone in it is stupid, as this article seems to suggest. I left philosophy because after all my reading, note-taking, class-discussioning, and debate tournamenting, I never felt like I'd made any progress, and that mattered to me personally. At the end of the day, the questions that were hard to answer were still unsolved, and the gray ethical areas were still gray. This is why I don't do philosophy, and I why I found the science bug. Not because philosophy lacks rigor or reasonable investigators.
In philosophy, real answers are difficult to find and prove, but in math and science, even though every answer brings 10 new questions, you can look back and say: I proved that theorem, I empirically verified the acceleration of the earth.
To quote my favorite xkcd T-shirt "Science, it works, bitches!". Most scientists I know that disregard philosophy do so because science gives them a feeling of getting somewhere, while philosophy, even at its most rigorous, just seems to leave them more confused than when they started. It's more of a personal preference for that kind of investigation than any rejection of the intelligence of a large group of people.