I don't see how mobile browser access to play.google.com constitutes a significant portion of the Firefox Mobile user bases core competencies. I don't think I've ever tried going to the store via browser on my Android phone just because its slower than using the native app.
You get there if you click links. It's not only this incident, Google often "accidentally" block other browsers for a day or two and then claims it was an "accident". Chrome seems to be immune to such accidents, though.
