Given that Tony Stark is usually in a leadership role in the Avengers, you'd expect that the team hadn't done much to ruin his life. After all, everything they do is under his orders, right?
Well, not entirely. Because Tony having this role more often than not leads to him being screwed over repeatedly, either because other members place too much pressure on him - because they judge him for having problems despite his prominent position - or because he funds the Avengers, and thus any moves that ruin the Avenger's finances also run him dry of money pretty damn fast.
And while Iron Man isn't always the perfect hero, he is always trying his best to do the right thing, which is why it hurts to see him repeatedly get belittled and sabotaged by pretty much every other member of the Avengers.
Although a decent chunk of this is somewhat justifiable, there are some moments - like making him drink despite being an alcoholic, or making him kill a teenage version of himself - that just seem outright unredeemable, especially when the Avengers are supposed to be Tony's teammates, as well as his friends.