I think it's fine to prefer other systems over class-based systems, but it is indeed a bit of a pointless complaint in a D&D based game. Personally, I think a really good skills system can be as good or better than class based, but it is hard to define and generally classes are an easier and more proven way of making characters customizable and add some proper reactivity. And in many classes - like Wizard - I think you should pretty much be required to dedicate most of your life to it to become really good.
