That's a really good question. Part of the problem, of course, is that the game is rigged: consider how difficult it is to buy food that doesn't feed the Nestle war chest.
As a society, I think there are moves in the right direction - I just stumbled across something called Community Wealth Building, which is very cool, for example.
But as a private individual? That's harder. I'd love it if there were an Amazon equivalent out there that sourced exclusively from worker owned co-ops, or at least unionized businesses, but as it is, I'm coming up dry...
Anecdotally, it would seem so.
I think it depends on the root of the hatred. An awful lot of hatred comes from ignorance, and when people dispell the ignorance, the hatred follows.
But sometimes the hatred is so fundamental to someone's lived experiences that even if it's obviously wrong, it's absolutely true to them. In those cases, I suspect it would be harder to let go of it.