I think the reason why people say 'niceness' is a turn off is because they make no distinction between genuinely nice people and 'nice guys'. And yes, there is a major difference. With people who are genuinely nice, there is nothing wrong with that, and it is not a turn-off. The problem is, there's a lot of self-professed 'nice guys' out there - I'm talking the guys who act friendly towards a girl solely for the purpose of eventually getting in her pants. They're usually the ones who go on and on about being 'friendzoned'. They see a girl that they're attracted to and want to date and act nice to her to try and eventually wind up on a date/in her pants. Those on the receiving end of these 'nice guys' affections tend to wind up very confused. Mainly because usually their romantic intentions are not made clear from the beginning - literally, they are being treated like a friend, so they believe that person is their friend and think of them that way, and then out of nowhere it turns out that the only reason these people were acting friendly was because they wanted reciprocation of feelings they never gave any indication they had. When they are informed that they are only seen as friends (because that's the kind of relationship they've been building) they tend to get angry and say things like 'nice guys finish last' or 'friendzoned again' and generally seem to think that treating someone like a decent human being entitles them to reciprocated romantic feelings/sex. This is where I think you get a lot of people who say 'niceness' is a turn-off and I think it puts a lot of girls on edge, too, at the disadvantage of genuinely nice people. Unfortunately, its really difficult to tell if someone's just genuinely being nice because they're nice, or if they're another self-professed 'nice guy' who's just treating them nicely for the sole purpose of getting with them later. There's no real way to know which variety of nice you're getting unless you're willing to take the risk and keep in contact with the person long-term. Certainly being nice and polite is not a bad thing on its own. But its important to be aware that there are a lot of manipulative people claiming to be 'nice' out there and that can cause some immediate caution or avoidance, and also that some people may be uncomfortable with certain traditionally 'polite' behaviours and that someone may not be put off by politeness in general but may be a little uncomfortable with certain behaviours.