It's not really a debate, the FSF, which was founded by Richard Stallman considers BSD (and a lot of other permissive licenses) to be Free Software. Only people who are even more of a zealot than Richard Stallman disagree.
My feeling is that they're not more zealous (to be honest, I don't think there's anything wrong with being zealous when you're fighting for a good cause) but rather dilettantes who don't actually understand what FSF is about, or what the various licenses precisely mean. They just find the general aesthetics and rhetoric of FSF and RMS appealing and try to emulate cargo-cult style.
