How I see it: if you were in the pre-ACA pre-existing condition pool, your perspective would be vastly biased in a different direction. And nobody wants to end up in that pool. Nobody chooses that. That's why it's a net win overall.
People died because they don't have coverage (unfortunately, still happens, but substantially decreased by ACA). If things are slightly worse for people who already had access, It's such a small price to pay.