As far as tier restrictions go I think you're seeing a trade-off from reality. Someone had mentioned that a low handicap is not required to go buy the latest and greatest driver, but a low handicap is required to hit that driver consistently well. Key word here is consistent. Anyone can fire off a good one now and then, but handicap is generally the determinant for how many of those 14 or 15 fairways you actually land in over the course of your round.
On WGT, we have a severely dumbed down swing system when compared to real life. On WGT, any hack tier player who can match up a meter to a strike line will hit a driver equally as consistent as any master and therein lies the disconnect. You wouldn't see that in real life, so WGT has to include that real-life element somehow. Without personal stats to modify, tier restrictions seem to be the only way to do that.
I think the restrictions are a good idea. When I play a Pro and we both nut our R9's on Bethpage #10, we're generally within a few yards of each other. The 25 yard club advantage was just nullified by the Pro's 25 yard tee box advantage.
I think we sometimes forget that they aren't making a game here. They're doing their best to make a true-to-life golf simulation that includes all the quirkiness and madness of the real thing. Sometimes that means we have to suspend reality and acknowledge there are certain things that must be done because a lump of code will never ever equal the real thing.
I think that making a quality golf sim with real life elements is more important to them than raw capitalism at this point. If they succeed on the first point, I think the money will take care of itself in the long run.