The problem with this is that games designed to be monetized this way are going to build their progression, reward-systems, cosmetic systems, grind balance, etc. around it.

So the players who are "paying what they want (mostly zero)" aren't getting a normal but free Diablo game, they are getting version of that game balanced and prioritized around the whales that /will/ be spending the money. The actual customers.

I'd rather pay than "free-ride", because I don't want incessant popups telling me how how I can skip the grind (that is tuned to irritate me) by buying a gems with my credit card.

I'm not as valuable to Blizzard/Activision/NetEase with my one-time-purchase though, and they know it.