It might not be his fault, but if he has to do it anyway, why not get paid for it ?
Second, time is a zero sum game. If the waiter has to spend several minutes wrestling with the POS to split a check, that's several minutes they can't be serving other tables, which if the restaurant is busy can mean a degraded experience for other diners (and of course if this leads to someone being unhappy with the service that will likely mean a reduced tip). Of course if the restaurant isn't busy and the waiter can afford to spend several minutes on this, then nobody else has to suffer, but if that's the case I wouldn't expect the waiter to balk at splitting the check (assuming they're capable of doing so at all, which as I said before may not be true depending on the POS or on restaurant policy).
While typically irrational for the individual, anger can be rational for the selfish gene, thus be preserved in the species: angry bees are avoided by other animals even if individual bees are suicidal, thus making the suicide of an individual work for the group.
So whenever you feel the need to go on a rampage destroying yourself along with your archenemy, you should really ask yourself if you are still in control, or you are executing out a program developed 1 million years ago and designed to protect the occupants of your cave from attacks of rival hominids, even at the price of your life.
A tip is fully extra incentive. The waiter is not my employee, and the social expectation of a tip is a horrible practice (imagine if we replaced the expectation with someone that wasn't financial in nature).
>And the kind of person that threatens to leave a bad tip if the waiter doesn't do something is the kind of person that probably tips badly to begin with.
This sounds kinda close to a personal attack. Not to mention there is a vast difference between threatening to not leave a tip ("if you don't split this check then I won't tip you") and what the parent post did (bringing up how refusing customer service right before a tip is given is likely to hurt the tip, never mentioning if this was a conscious or subconscious behavior change made by the tipper).
2. If a waiter spends 10 min at the POS splitting a check, other tables are being ignored and management might not like that.
Interestingly enough, a server works for three parties: guest, restaurant, and themselves.
Sucks but true. Gotta choose lesser of three evil sometimes.