I'd say that I have a theory/explanation for why I think this is the case: In the hands of creative people, Strats (in its many incarnations) can sound great and totally unique. Nothing quite sounds like a Strat, right? (ask Frusciante, Clapton, Gilmour, Mayer, ... ) But also, the Strat is a guitar that can mimic successfully many other guitars. Can it sound like a tele? Yes, to some degree. Can it sound like a semihollow? Not easily but it can get in the ballpark. Can it sound like a Gibson solidbody? With the right pedals and amps it's not entirely impossible. So, summing up, it's an instrument that has being around for ages, can be produced cheaply and can sound unique or derivative (and I'm using that word in a positive sense) depending on the player. Do you agree?