Why do people suck?

So fed up with my "friends", or I guess people who pretend to care to our faces.  Been slapped in both cheeks a little too much recently.  I am TRYING so hard not to stop being who I am and just avoid people all together.  It has been difficult recently and I think it SUCKS that people can be mean, hateful, use others and not think one thing of it.  Be inconvenienced one bit... and BAM, their world comes to an end.  I always help others as much as possible.  To a flaw, most would say.  I never ask for anything in return and I am ok with that.  When I feel used, it is hard to keep it up.  I know I probably should continue, but I am trying to heed the message that sometimes people should not be in your life.  I do need those people removed.  Some days I wish it were easier, neater, and cleaner... it never is.  We always want the easy way out.  Hahaha.