I agree with you, however, I've experienced enough of this stereotype firsthand to basically dismiss most business-types immediately. It's just not worth my time to find the "real" business types, for the same reasons pg mentions in his essay [1].
It depends what you're looking to do. If you're doing commercial targeted software, they're invaluable because social media etc. often don't move shit. If you're doing a standard consumer play, they might have less effect.
[1] http://paulgraham.com/start.html