Don't get me wrong, a is reprehensible, but you're conflating b which honestly is a good thing, with "organize an event that implies inundating people"

from the site: "We can’t force developers to change their code - but eight hours of pull requests from ethical coders the world over might just make people stop, think, and change their ways."

In context this sounds like a bully tactic, regardless of how good of a cause it is.

Edit: it looks like they've addressed the idea of spamming developers in their FAQ now, so this is basically all moot.