For a buyer on a tight budget, the only chance they may have to find a good watch they can afford is to dedicate a lot of time and energy tracking down obscure sales and auctions. Someone like that is not going to appreciate a dilettante waltzing in and publicizing an auction, for no good reason. "Woohoo, I found an auction, look at me!"
If you post an ongoing auction for a highly desirable watch, you'd better be doing it because you have questions about the watch and can't get the answers any other way (e.g. by PM). And then if the watch checks out, you better be prepared to bid seriously and win the auction. Because the chances are good you ruined it for someone else and raised the price for yourself. Just adding one more bidder to the mix can make a big difference.
And why would I publicize my watchmaker's name and contact info so any jackass on the internet can say I referred them to him?