I suspect that it's because they embed some Spotify thing for their shitcast at the bottom of the page (I refuse to let them use the established term for such a

I suspect that it's because they embed some Spotify thing for their shitcast at the bottom of the page (I refuse to let them use the established term for such a DRM-walled ripoff of the real deal). I know for sure that Spotify's regular web interface requires Firefox's DRM plugin, because that's the reason I run it in its own VM.