I've lost count of how many times I've googled a question, had the first hit be SO, and the top answer to the question be "Have you ever heard of Google, n00b"? (Thread locked).
I've lost track of the number of times that I've gone to a question that actually deals with what I'm looking for just to find that it's locked and marked duplicate of a completely different question. Complete pain in the ass.
Then there's also the conceit that SO has hit upon a definition of what a good technical question is (or, more specifically, what isn't a valuable technical question), and they stick to it despite any evidence to the contrary. I've seen questions that fail their over-restrictive criteria that have far better answers than many that do.