>If the product is buggy, isn't the QA to blame and should thus get the axe first?

Obviously not.

While it CAN be, one much more common issue is project managers death marching the developers with impossible deadlines and tons of hard features for the next release, and then rushing to market when it's not yet read.

The QA can file all the bugs they like and do a perfect job, but developers can't fix them soon enough, or they fixing requires working around complex architecture choices that were done in a hasty manner.

Think of open source projects with thousands of open bug reports submitted by users (thus serving as QA team in this case). Is it the fault of those users that the bugs are not fixed?

Possibly. But it could be the QA team is great but the pushback from management is to let buggy releases occur. It happens, especially when it affects the bottom line.