Is Hanzo troll?

He is not a troll he can be really good hero in the right hands and people just want to blame the lost on everyone other than themselves

If you play it good, then you can carry and no one will complain, but you cant limit yourself to one hero only

That's because you probably play in lower ranks and people rarely see a good hanzo in these ranks. If you can play him well he's a very good hero and he's picked a lot in high ranks.