Too complicated
A wheeled vehicle has far fewer moving parts than one that uses legs to get around. The more parts, the more opportunity for things to break. Face it, it's hard to get much simplier than a wheel.
I think the Lunar Rovers bounced around so much because they were quite light and because the astronauts tended to drive them too fast. Given their very limited EVA time, it's easy to understand why they'd be in a hurry to get where they were going. Perhaps that won't be as big an issue when there's a base to return to and you're talking about staying on the surface for weeks at a time.