On the other hand, more players means more bandwidth and more server usage for Blizzard, which means higher costs. If everyone plays and doesn't buy anything, then they'll lose money on server costs.
There's no version of "I am gonna stick it to blizzard" that is concordant with "while continuing to enjoy their products." It's just rationalization because people want to minimize the cognitive dissonance that comes with maintaining their routines.
Blizzard does not have free-to-play titles because they are such kind people that want to help others out. They want a community that is engaged in the titles, that talk about it, watch videos, play it. Some of them will pay, and Blizzard wins. The thing that really hurts them is if you, yes, you, delete your account. Stop watching videos about their games, stop talking about them. Everything else is simply still supporting them, no matter how you twist it.