> Epic gets everyone who would buy that game on their platform (minus the people who are outraged by the exclusivity deal)

IMO, it's more about a game store's expected longevity.

At this point I will probably never spend money on a game that's not on Steam (unless they go out of business) simply because:

1. I've gotten burned too many times by non-Steam stores that have later gone out of business.

2. Steam works really well.

I suppose a few people might be outraged by exclusives. I think most people just want an experience at least as good as games-on-dvd.