The sad thing is that despite the clear evidence ("real women programmers read it as a gendered term") we'll no doubt see a ton of posts on this thread arguing that it's clearly not a problem.

That said, I'm reasonably sure that it's not intentionally exclusionary. The poster had an image in their head of a work environment and came up with "brogrammer" as a catchy way to describe it. That this picture didn't include women is a huge problem, obviously, but I suspect it's probably not willful sexism.