The number on the page is a bit misleading. If you comb through the website's code on GitHub, you'll see that the 8,838 is actually the number of subreddits that agreed to participate in the blackout.
Calling it a flop isn't accurate either, though.
Sure, most subreddits don't care, but the largest and most active subreddits are overwhelmingly in support of the blackout, but they are also much more affected by Reddit's changes than smaller subreddits.
EDIT: Some words for clarity.
I'm out of here if the community stays up. I've already blocked it, but we cannot be tolerant with the intolerant.
They need to go, and other instances would be right to ban. That's the only way this model works.