I can't speak for everyone else, but to me personally, it's because I'm not okay with u/spez making cash with my years of unpaid volunteer work while simultaneously spitting in the face of every content creator and half the userbase. NGL, It sucks that this action hurts the community the most, as redditors now no longer have access to the removed content, but "just leaving" while the content remains intact and public means that u/spez can just shrug it off and continue the shitshow undisturbed. He didn't get the hint during the blackout - maybe he'll get the hint once the site is exclusively filled with trolls, bots and scammers and devoid of actually interesting stuff.
Long story short, a website is only as interesting as the content it offers, and if you take the content away, you remove the incentive for people to visit said site.