I could not agree more. I am a mechanical designer, using CAD, by trade.

Simply knowing CAD does not make one a designer. Spending time in the shop, learning the capabilities of lathes, mills, 3 and 5 axis machines, wire EDM, different types of welding from EBM to TIG to MIG will teach you more than any class room course. Some hands on experience doesn't hurt either.

At least with models you don't have to risk your life trying to prove a point. Still there must be a few guidlines for designing models, such as choising the right airfoil for a particular application.