Do men stay with a woman only because she's good in bed?

Do some of you men really stay with a woman ONLY because she's good in bed? Not because you love her, or because she stimulates your mind, but because she gives good head? Are there men out there that shallow?

My colleague broke up with his girlfriend and when I asked him what happened, he told me sex with her was a bore, that he wanted to try something new. 

When my boyfriend and I broke up, the first question my brother asked me was 'weren't you giving him good head?'

Then just recently, a friend of mine told me that the only reason he's dating his girlfriend is because she gives him the best sex ever! Are these three fools the last of their kind or are there more men like them?