"but I'm a nice guy" (How many people don't think that they are 'nice guys'? No, I'm a dick, thank you very much) and it is DEFINITELY a trope from the angle of the blogs and online think tanks that have come up with the idea of the Nice Guy™ as yet another stereotypical model in the production line of horribly defective modern males.
And again, usually the people who are putting profiles on online dating sites aren't terribly successful at finding partners to begin with.
Edited to add: Also, the attitudes apparently displayed by some of these guys are really fucked up, no question- but with stuff like "I think men should be the head of the household" or whatever, you could probably find thousands of similar statements or attitudes on any "Christian" dating site. Which is, again, fucked up.
(It's odd that, isn't it, that certain corners of online thought give such a regular, reflexive free pass to the religious right. 
)
Edit history
= new reply since forum marked as read