Not if it provided classes on top of the skill- and feat-based system. After all, designing NPC Fighters and Experts isn't a nightmare now.A skill based system for D&D would make prep time and NPC design a nightmare. IMO.
Actually, the system could use subclasses too -- 1E-style classes with no wiggle-room, defining what an Nth-level Knight, Archer, Pikeman, Spartan Hoplite, etc. looks like in terms of skill and feat choices.