DISCLAIMER: this is purely based on observation, both personally and based on direct descriptions from other people. It is also written from a male perspective. Everything in here can be reversed, and apply the other sex too. I will also not pick up the element of fake nice guys, so i will only talk about/to the genuine nice guy.
"nice guys finish last" and "girls only go for asshole players". Wonderfull statements, aren't they?
Especially since there seem to be something to them, but maybe for all the other reasons than you think. I'll just go ahead right away and spoil this take; nice guys finish last because they're often boring. Girls go for asshole players because they're interesting and exciting, they seem to emit an aura of "control", and they seeem to have his shit together.
Being nice is not enough!
That is why you nice guys finish last. Because being nice is not enough. If you want a girl you need to have more qualities than being nice. These qualities vary between each girl, but generally it all boils down to making her feel loved and give her that tingly feeling you get when falling in love, about making her smile and laugh, about making her proud to be your girl, and about having a certain chemistry and compatibility.
If you can't do that, you'll never keep her. Hell, you'll most likely not manage to make her fall in love with you to start with.
Bad boys often have those abilities!
There, i said it. Surprised? bad boys, while sometimes acting as total dicks, DO stuff! They don't sit around, they gets out. They have fun, they create that thrill. So as long as she likes the same things as he does, she'll have a blast! She may think he's awesome! because after all, she haven't had this much fun, and had this strong chemistry with a guy in a long time. So he must be perfect, right?
But why can't she see he's a total dick?
"Infatuation, blinded eyes, she never saw his burning lies"
When we fall in love, at first there's a period where everything is perfect, nothing is wrong with him (or her), and life could never be better, ever. This is called infatuation. She is figuratively speaking blind. Guys experience this too, but from observation it hits girls harder, and lasts longer.
See the connection? Infatuation puts her in a state of euphoria where she blatantly ignores and overlooks all signs that he's actually an abusive douchebag that she best stay away from. This is why every guy (and often a lot of the girls too) can see his true coolors, but she keeps on ignoring them, saying he is perfect.
Then reality hits, and his deception falls.
This can take days, weeks, months, even years. And this is when things start to go downhill. Ever noticed how players can never keep a girl? Because of this.
The stage of infatuation passes, and she sees how he really is. Within a short time he goes from perfect to asshole player ex. Sometimes there's a period of denial involved, but eventually she'll want to leave.
How the genuinely nice guy can handle that.
Be interresting! Go bad on the outside, and stay nice on the inside.
What i mean with this is to DO things, get a hobby or two, maybe three (ideally one of them should keep you decently fit). Look at the bad guys; what do they do to make her smile and laugh, make her have fun? You can do that too, in your way! I'm not telling you to pick fights, get smashed every weekend, and fuck all the girls, i'm just telling you to offer more of yourself, be more active. Do things that makes you feel confident in yourself! Be a person that is fun and exciting to be with, be that guy that makes a girl giddy. Go bad on the outside.
But stay the kind, loyal, loving, and understanding person you have always been. Stay nice on the inside.
A simple illustration of why this works.
Becase there's a simple line of preferences that roughly sums it all up
interesting/exiciting nice guy > iteresting/exciting asshole > boring nice guy > boring asshole
Simply put it matters more to be interesting and exciting than to be nice. Sure, going bad boy will get you up one notch, but a genuinely nice guy can get to the top. You will be better than the bad boy.
Girls pick bad boys over nice guys because bad boys are interesting, and interesting trumphs being nice. They keep the girl for a while because infatuation prevents the girl from seeing he's a total asshole.
But a nice guy that is interesting will generally be considered better than an interesting bad boy.
So nice guys out there, BECOME INTERRESTING and EXCITING. Because girls first look for "interesting", then looks if the guy is nice or an asshole.
Thankyou folks, that should be all. And bare with me if there's elements i have forgotten. And keep in mind this isn't necesarily the only reason, but it seems to be a frequently reccuring reason.
(image because GaG says i need one)