Goodness, I don't know what is wrong with people these days, but you see this kind of stuff all the time.
It's become such an "all about me" world. No one wants to take responsibility for their actions, and blame everyone else. People treat other people with loath and disrespect.
I find myself getting very cynical and that really isn't like me and it really bothers me that I have gotten this way. It's hard not to though.

I guess we just have to learn to not let these kinds of people get to us and know inside that we are good and do our best. These others are just miserable and because of such, want to make everyone else around them the same way.

Try not to let them get to you. I know it's hard, but just count to 10 and think to yourself how happy it makes you that you are not such a miserable person as they are. Then look them square in the face and tell them with all the sympathy you can muster, how sorry you are they have such miserable lives that they feel they must make everyone else the same way.
Do it with a smile and sincerity and then turn and walk away.
They won't know what hit them, and this keeps you from lowering yourself to their level.
Now I need to learn to take my own good advice.