Yeah I don't trust guys who say that.
It's a sketchy litmus test. When I first started dating my DH, he said that to me that "women don't like nice guys. They're only attracted to jerks." It set off all alarms in my head, but we'd known each other for years and so I took a chance dating him anyway. He's fantastic and we've been married nearly 10 years now. So there are some nice guys out there who subscribe to this too, but most jerks use the line to gain sympathy.
I've found that there are people (men and women) who are really nice, and make great partners/spouses when matched with the right person, but who have real trouble *finding* that right person. Some are shy or a bit awkward, or late social bloomers, some need someone who 'gets' them and their outlook on life. Some are simply unique people who fall outside what is considered mainstream and desirable in a partner in more external things, but are great in the more internal things (commitment, treating someone right, responsibility). Geeky girls and effeminate straight men, for example, can have a hard time on the dating
Then there are the guys who *aren't* nice. They think they're such an amazing catch that women should be falling all over themselves to be with them, and when that doesn't happen (usually to one or more whopping flaws) it's obviously the fault of those witches.
And there's an intermediate stage. Guys who are reasonable nice guys, maybe with a few quirks. But they have bad dating
skills, and scare off women who would actually be interested in the person behind it. So they get angry and disillusioned because they don't understand why they aren't succeeding.
I have a colleague who I think is drifting into the last category. He's a nice guy, and really wants a girlfriend, but I have a feeling he's scaring off women by being too intense and focussed on that goal. Plus, he has trouble grasping that while *he* knows he's not a creepy stalker dude, the women he's chatting up don't, and he has to adapt his style so he doesn't give that impression, even if the motives behind his behaviour are innocent.