Actually, its been shown that the confusion of which account type to use is worse than the bonus of having options at signup. I forget who did the testing, but non-techies have trouble remembering which they used as well as understanding what it means to "sign in with..".
I'd be interested in seeing the study. For me, at least (and I think for many others) the thought of creating yet another login is enough to make me back out.
Okay, I misremembered a bit. They showed that a tiny portion of people used social login (~3%) and that the gain they thought they'd made with them (fewer forgot password/username issues) was due to an unrelated change. The tiny portion shows that it can't be that important (plus, how many of the 3% that took advantage of it would have left without those buttons?).
I apologize for the misinformation in my first comment, but I think my point remains. That said, I feel similarly to you - I just think that a much smaller portion of people feel that way than you realize.
