Play a different game first that has it's game mechanisms specifically designed for a different game style of play, like a Fate Core of Cortex Plus game or perhaps Burning Wheel. Because these games are designed around a vastly different paradigm than D&D/Pathfinder style games, where proactive character design and the overall goal is a more story focused, narrative driven game system these games could show players like you are describing a different way of how to play role playing games. Even using Supers Revised Edition could be a good change of pace, and it has a superb random character generation... I know it works because I bought the pdf, flipped to the random character generation chapter, and made a complete character using the charts and never read the book.
Right now they are so used to number crunching-min/maxing rpg systems that they will only take what they know and apply it to whatever game they go into. Games like Fate Core change that paradigm because it's truly different enough in it's focus and scope that one of two things will happen... either these players will become aware that there are actually different styles of playing these games that can lead to newer and fresher experiences, or these new games will be so different to them that their minds will explode and they won't be able to handle it, and either way you learn how versatile your players are.