Intensely weird. But then aren't we all? Why strive for normality when you can do what you enjoy?
Is it how everyone plays? No. Does that matter? Not even a little bit. RS is a game designed for you to find what you want to do and to focus on that. Sure, I think you should be doing the epic questlines, but if you get your enjoyment out of mining a rock or cutting a gemstone, then who am I to judge?
OK, fair enough, I judge everyone, all the time, for everything, so perhaps I'm not the best voice to wade in here.
Translation: You do you, as long as you're enjoying yourself you're doing it "right".