As far as easy to grow, I don't know, I don't have the greenest thumb in the world, but it's been pretty darn hard for me. Then if you start talking about real quality, as far as I've seen from some documentaries, it requires a lot of dedication and knowledge to get the kind of quality that I'd smoke consistently.
I guess my point is, practically speaking, I see 99% of people still buying it even if it's totally legalized and not taboo.