He was far from a one hit wonder. That is not in anyway true. He helped to create a musical genre that didn't exist before him. Nashville finally went to the beach long after Jimmy did. He was an excellent songwriter and a consummate performer. He cared that his audience had a good time. He would play what he thought they wanted to hear and so if that was fuckin' Margaritaville, so be it. Do you think you could get Billy Joel to play Piano Man today? He'd probably tell his audience to go fuck themselves if they asked.
If you think about it, it makes sense that Jimmy was an excellent businessman because he knew how to put people at ease, he was charming, and he knew to put smart people in charge. As an investor, if you met up with this guy, how is it that you wouldn't open up your wallet to what he asked? Sheeeeeit.