I disagree that the rick roll is inappropriate, but i also hate the argument that just because its open source, the programmers are above criticism. I think its reasonable people can dislike or even morally object to the decisions open source maintainers make (even if i dont particularly object to this specific instance)

They're not above criticism, but what they've done is a very small layer that's easily removed. You can do it, and release a version without it, in minutes. You can do it in less time than it takes to write a long comment decrying it.

It's not fundamental to SD in any way, and their suggestion wouldn't have worked.