I'm giving Tom Petty a listen on Play Music right now, and Runnin Down A Dream is laughably simple. But it works. And like most rock bands, all of them can play better than I could ever dream of.
See, I don't know what "it works" is supposed to mean in this context. Of course, going versus-chorus-verse over 1-4-5 "works" (though that's a hugely subjective statement anyway). If by it working, you mean it sold well and it gets in your head, then yeah. But I would argue that music operates by supply side economics and there were any number of songs released that same year that were just as catchy but didn't get the exposure.
I don't
hate his music, ftr. There are many things out there that are far worse. I just don't think you can call him brilliant, even in the context of pop. He doesn't compare favorably to other recently dead musicians like Bowie, for example.