Why does society think all war veterans are crazy?

Because it is typical for war veterans to be crazy. There is a chance that there are a few people that could be put in a war and survive without any mental effects but that is rare to find, unless the person happened to not have to go into combat and/or see any of their teammates or friends' dead bodies lying around. It's never the war veterans fault but seeing a huge number of other humans bodies getting demolished, tortured, killed, blown up, etc. can cause mostly anyone to become crazy, especially if their mind is not ready for it, not to mention that they had the fear of having to kill others, and possibly being forced to die which will definitely scar someones mind for years to come. The veterans are people just like us but it is wise not to startle them or anything of that sort, and some can act completely normal if they aren't scared but they still will most likely have nightmares.

In general vets see the world and the results of politicians actions far, far more accurately that does the general civilian population. That also means vets are more in touch with reality.

nobody wants to go to war

Because most of us are...just not the way everyone thinks we are.

That's a pretty broad generalization you're making, kid!

Because of the liberal media.