It depends on the guy. It is true that girls do not find 'kindness' attractive by itself. You need to have other positive and attractive attributes in order to be considered attractive. Niceness by itself is not attractive. I would argue that niceness is a baseline requirement.
You can make an easy comparison. Suppose that you have a fat short ugly 5 foot guy who plays video games in his mom's basement all day. A girl will never find this guy attractive no matter how nice they are, because they lack so many attractive qualities. Being nice will never get this guy the girl. However, compare this to a guy who is 6 foot tall, has a nice ferrari, strong jawline and six pack with lots of money and a good job with amazing social skills. He will be billion times more attractive then the first guy. He will get far more attention and positive reactions from women compared to the first guy.
I do believe that the bad boy theory is true. Girls do prefer guys who don't care about them and don't show them any attention, because not only these guys are a challenge but they also show that they are of higher value. It is all about how you perceive yourself. If you act like you're nice and suck up to her then she will think that you're below her, but if you show that you don't give a sh*t about her then she will think that you're not trying to impress her and she will see you of higher value and show you respect. Also, nice guys can't take initiative and are scared to talk to women. The phrase 'Nice guys finish last' is true because these guys wait for women to approach them, but women never approach. It's how it is. Women don't approach unless you're a god alpha male with a juicy jawline. Some nice guys need to try to take initiative, learn social skills and understand female psychology.