He's wrong.
Proper mounting is essential no matter what ski/binding you're using, but some skis and bindings, when put together have a higher chance of problems occuring, it's just a fact.
Bindings with tight screw patterns are nice because they do very little to disrupt the natural flex of the ski, but the trade off is that on cetain skis they tend to be easier to tear out. Skis that are very wide are prime examples, the increased torque put on the binding/ski interface causes more stress, and therefore a higher likelihood of a rip-out, particularly on skis with soft cores.