Why do people despise the troops?

Being a member of a family with soldiers in it, I find it incredibly offensive when I see groups on Facebook such as "Soldiers are not heroes, they are tools of war" and other anti troop nonsense. I can respect this sort of opinion if people are truly opposed to the war, but saying that no war was ever necessary is incredibly far fetched, most soldiers genuinely care for their countries and wish to defend it; they aren't sadistic barbarians with the sole intent of murdering innocents, and it's certainly not as if most of them are paid a lot. I've also heard plenty of anti war quotes such as "There will always be war so long as men go to war" and such. How is it logical to not go to war if you have already been attacked? No intelligent person would just sit there and let their country be destroyed for fear of going to war and resorting to "violence". Is war an evil thing? Of course, if it was possible for us to never have to go to war that would all be very nice. That's not the kind of society we live in though; there will always be war so long as mankind exists. Apologies if this category was misplaced.