It seems out of place to us, people who have accounts and know what those other icons are. To someone unfamiliar with the network, those icons probably won't get much action anyway. That leaves people familiar with the network but who aren't members of that particular site, which I suspect is a very small portion of the visits to most sites.
As noted in another answer, SE tested this with the target audience and found this to be the best position. That's not going to change. I'm only adding this answer to add another reason for the placement not being as bad for that audience as it is for us. I upvoted the question when I first saw it, but I now realize that that button isn't aimed at me anyway.