Why do conservatives always talking about liberals whining when they whine themselves?

Yes, it is hypocrisy. Both sides whine. And both sides whine about the other side whining.

It's much easier to see faults in others, especially your "enemies" than it is to see them in yourself. 

*like*

https://en.wikipedia.org/wiki/Psychological_projection

*like*

everybody's a hypocrite sometimes.

the reason is...  Opposition Defiance Disorder.

Whining is unjustified complaint in weak pathetic way when you should just suck it up.

Liberals and conservatives have very different ideas about justice. They're never going to agree about what grievances are valid or how much complaint is justified. So I guess each side is bound to consider the other side whiny. It's not hypocrisy, just a different point of view.