If someone doesn't call a foul on themselves, I would not necessarily label that an act of unsportsmanlike conduct, or poor sportsmanship. If it were, then catching someone in the act would have some sort of special consequences appropriate for unsportsmanlike conduct. Not calling the foul on oneself, I could concede that that's neutral sportsmanship in cases where the opponent had an equal opportunity to detect the foul as the shooter did.
However, if someone does call a foul on himself, that is an act of good sportsmanship. Plain and simple. If you fail to exhibit an act of good sportsmanship, is it necessarily poor sportsmanship? No, not necessarily. But I disagree if you say that calling a foul on yourself is not good sportsmanship.
Please don't disagree with positions that I have not taken! (-:
If I felt that having a written rule stating that players are supposed to call fouls on themselves would actually make more people do that, then I would consider writing to the WPA. The problem is, there's not really any practical punishment for failing to do it. So, IMO, if someone got caught in not calling a foul on himself, all he has to do is say, "oh, I didn't realize I fouled, sorry".
Well AT LEAST having such a rule would justify complaining about a failure to self-call. As it is now, there is a debate on both sides of the issue which suggests a shortcoming in the rules.
I don't think you a written rule is necessary to know that it's good sportsmanship to call fouls on yourself.
If I tapped the cueball, the punishment is ball in hand. If my opponent isn't getting ball in hand, then the rules aren't playing out the way they are written. I then tell him it's ball in hand, so that the rules play out the way they are written. The only reason, IMO, why we should have to call a ref over is for shots where the shooter and the opponent might genuinely disagree on whether or not there was a foul.
Hey now, I am only exhibiting a minor abuse of logic at the worst.

And I think the revered sports champions will get over it.
Seriously though, Jim, I don't think you are comparing apples to apples here. You cannot make a fair comparison between a self-refereed pool match with option to call over a tournament director who in many cases is just volunteering or is being paid a small fee, with a wealthy sport like American football, which has well-paid professional referees. If you want to talk of pool matches with well-paid, well-trained refs, then I won't argue with you, but this isn't what I'm talking about.
The wealth of the sport and the professionalism of the refs isn't the issue. The issue is whether a player is required by RULE to self-call fouls and whether a failure to do so is immoral or unsportsmanlike.
Clearly, it is NOT a rule violation so that leaves us with the sportsmanship issue and that is where the slope gets VERY slippery. Sportsmanship is a loosely defined term in the first place and has WIDELY varying standards from one sport to the other.
Where is the sportsman line drawn in Ultimate Fighting...not sticking your finger 3 inches into the opponent's eyeball?
So, we look to all other sports to discern what the AGGREGATE thinking is. So, we are not comparing apples to apples but apples compared to ALL OTHER FRUIT in the basket. And that is the RIGHT thing to do.
The AGGREGATE shows very clearly that not self-calling fouls is perfectly sportsmanlike. Therefore, making it unsportsmanlike in pool DEMANDS A REASON why pool should be held to a higher standard than the aggregate and so far, no one has offered any cogent reason for such a higher standard.
The RULES empower a player to call a foul on his opponent but do not provide for self-calling of fouls.
Please explain to me how someone could be in full complaince with the rules and still be unsportsmanlike.
Well, both sides could write to the rules committee, not just me. I mean, where in the rules does it say something to the effect of, "a player should not feel responsible to call a foul on himself. If you foul, you should act like you didn't do anything unless and until your opponent calls you on it."?
Cheers,Cuebacca