I don't think Kurt Cobain had mainstream success and record sales as his primary goal when he wrote "Smells Like Teen Spirit". Certainly no more than Husker Du, The Replacements, the Pixies, or whoever else preceded them.
Whatever you think of Guns and Roses, I think it's sort of silly to lunp them in with hair metal bands. I'm not the biggest GNR fan in the world, but I think they themselves started a musical move away from hair metal fluff.
Of "Smells Like Teen Spirit," Guns N' Roses bassist Duff McKagan said: "That was really a breakthrough for a great scene that had been going on for a long time up in Seattle. And it was kind of another victory, I think, for a misunderstood music, you know. The dam broke when 'Teen Spirit' came out."