Pro boards are a fine tradition that has stood the test of time. Pro trucks, bearings, hardware etc is some silly shit.
Why? It's the same shit these days.
Way back, you bought a Pro board for that pros shape, because you dig it, the pro, shape or company.
These days, boards are not so dissimilar and less so within brands, so how is buying a 'Pro' real deck in your favorite dims any different than a truck, bearing, grip or a wheel? You are still supporting that pro...
There are so few pro custom shapes (that they actually ride) to make that purchase special, and some companies offer amazing shapes that are never or rarely ever pro shapes (quasi comes to mind).