Man, I could not disagree more. To me, system matters. Star Wars makes for a very different game in WEG's D6, Wizards of the Coast's D20, and Fantasy Flight Games' Genesys. It would be even more different in Savage Worlds or GURPS.
Even in a game like TORG, which is explicitly multi-genre, the different genres are given different mechanical expressions. The difference between the Living Land and Tharkold is not just that one has strong miracles and the other strong tech and magic – they also work differently. The Living Land is a world that rewards living life to its fullest, acting on primal instincts, and taking risks, while Tharkold is a place where the strong dominate the weak and inflicting pain is rewarded.