RpNation

You could alternatively be completely selfish and only act out of your own interests.

Yeah. You could. I never said you couldn't. But then you're directly contributing to the evil and injustice in the world, and making it actively harder for those who give a crap about being nice.

You'd really be literally no better than the rest of the unjust world out there. Those who only act on their own selfish interests and desires are the robbers, rapists, abusers, killers, and manipulators of the world. They are the ones who take advantage of the weak, naiive, or even merciful. Selfishness causes unjust.
I suppose if one is entirely selfish, it wouldn't matter to them, though.

It's a sad way to live.

I'm not saying that you should take advantage of the poor and exploit them. I'm merely suggesting that you would get far more ahead if you simply acted in order to benefit yourself. It's not nice people at the top. Maybe they become nice once they get there but on the way there they had to be ruthless.

It IS possible to act towards a better future for yourself while being kind and loving to others. You don't have to do one or the other, you know. You're not selfish for looking out for yourself, you're being practical.