In its most basic form capitalism is a predatory economic system. Upselling, advertisements, all of it is to help sell product. That's one reason why this conversation is ridiculous.
Blizzard shows you an ad in a game. The sky falls in.
Network TV shows in the U.S. run 20 minutes of ads in almost all programs/productions. People say little or nothing about it. And for good reason. The choice is to watch the show, not watch the show or wait for it to show up on some streaming channel that you're paying extra for to avoid ads.
The basic root cause of all the complaints is that Blizzard and everyone else is engaging in capitalism. It's a pointless argument.