Do you all go back to the stable after a horse race and jelly the jockey?
It's a side gamble pure and simple. Players are there to compete for the purse (and side action in some cases) the same as any other athlete.
How does golf handle this sort of thing? Seems like a similar situation exists in the golfing world.
It isn't a side gamble pure and simple.
The only customers at a racetrack are the bettors and that's what they go there for.
The PRIMARY customers at a pool tournament are pool players and they go there to play pool.
The PRIMARY Calcutta buyers (by number) are the pool players, not bettors who try to figure a way to lock up the Calcutta money.
How much money does a Calcutta buyer spend when they are a tournament? Probably a tad more than most pool players but probably not much more, not as far as the house is concerned.
I'm not a Calcutta hater by any stretch of the imagination. In fact, for me, it's just the opposite. I think the Calcutta buyers that don't play in the event are awesome to have around even if they do pick the pockets of the pool players. Occasionally they may stake a match and they tend to tip well so they are always welcome wherever I go, in spite of their propensity to open my nose for sport. (It's true, that some Calcutta buyers actually bid up certain players just to get a rise out of them.

I could name names of Calcutta buyers who do that on a regular basis and they pass the whip around to different horses from time to time just to entertain themselves and others. It's all good. I know it's just for fun.
Here's what I see:
The Calcutta's vitality must be maintained.
The Calcutta buyers MUST be protected from "business".
There's nothing wrong with getting this "tipping business" out in the open.
I hear SOME VOCAL PEOPLE claim that they tip 10, 15 & even 20% to the player, although I haven't been the recipient of such generosity, I'm sure it exists. Maybe it's because I seldom visit the winner's circle or maybe I just miss hooking up with one of these philanthropists. I also seldom see Calcutta buyers tipping this way so maybe your perspective is the way things really is; maybe the Calcutta buyers just don't tip as well as some insinuate. Maybe they do. Either way, it appears that the calcutta buyers make a habit of running up the players value in order to build the calcutta, sometimes to the chagrin of the players to the point, where the player cannot afford to purchase half of himself. The Calcutta buyers form corporations so that they can manipulate the purchase of the best horses. It's done all of the time. The players/horses are performing, spending enormous amounts of time and money to come and play in these events.
I JUST DON'T SEE ANYTHING WRONG WITH THE PLAYERS BEING COMPENSATED BY A TOKEN FROM THE CALCUTTA MONEY. How that is accomplished is a slippery slope and I would hate to see any change in the Calcutta to undermine the event or the Calcutta but furthermore I would hate to see tournament promoters, pool room owners thinking that the "Calcutta Green Fee" belongs to them, to do with as they see fit. This would probably be the end of Calcuttas wherever they are held. An owner taking a profit from a Calcutta would almost always be perceived as a gambling enterprise by big brother and they would most certainly be shut down when the local constables found out about it.
I'm not a golfer so I wouldn't know what they do but I've never heard of "the golfing community" holding a Calcutta. I have to believe if the PGA had such a thing, that pie (Calcutta) would have a major slice carved out of it for the PGA before the players/calcutta buyers saw a morsel. The PGA then could dole out any profits derived from the Calcutta holding back to the players as they saw fit.