TotteSwede: Illogical because I can use any kind of clubs in real golf regardless of my skill.
This was the argument back when clubs were tier specific. The way it is today is ostensibly the result of that discussion (or was in WGT plans to begin with.) The problem the change created was that the better clubs, in the hands of the lower tiered players, created an imbalance with no incentive to move on.
TotteSwede: Bad for business for WGT because they would sell less clubs and there wouldn't be a way for "less good" players to help their scores by getting better gear.
I disagree. As it is now, level up and you can buy what you want. Tier specific clubs would limit what you could buy and tiering up would create sales of the upper level clubs, unavailable until the specific tier was attained. That doesn't happen now because the clubs can be had just by playing enough.
While the argument is valid that you can buy anything the pros buy, the difference in your hands versus the pro's hands would be quite large. In this game, simulating reality, I would think that making tier specific clubs would balance out that difference.