@H, You're absolutely right. But I think Zander said it best:
Why do you even care?
Seriously. Stop wasting energy on giving a shit. It's never going to change. The simple fact of the matter is, the overwhelming majority of people aren't HUGE music fans like most of us on this forum. They're perfectly content with enjoying catchy songs on the radio now and then. They don't need to listen to stuff like Porcupine Tree. It isn't made for them. In the same way you could argue that mainstream pop music isn't made for us. They're missing out, but who fucking cares? That's on them. It isn't hurting them, and it's not hurting us that they don't like what we like.
Certainly, I'd like to see bands like Opeth and PT get more recognition, because they deserve it. But they're doing just fine right now. They have strong, devoted fanbases, and as far as I know, Mikael Akerfeldt isn't scrounging for thrown-away pizza in alleyway trash cans. They deserve more than they have, yes, but I think they belong more in a niche music scene than the mainstream anyway. I don't really want everyone to know who they are. If Opeth was a household name, I suppose that'd be cool. But I don't get offended that Poker Face has more views than all Opeth videos combined, because, at the end of the day...it just doesn't fucking matter. I enjoy it, you enjoy it, your neighbor has no idea who the fuck Opeth is. Life goes on.