After judging a Standard PPTQ in which Kalitas saw a decent amount of play, I've concluded that it is secretly a terribly designed Magic card. Many, many players were forgetting both the exiling and the tokens, and to many of their opponents getting tokens "felt" so much like a triggered ability that they continually, instinctively treated their opponent missing their own Kalitas the way they do missed beneficial triggers.
FYI:
Kalitas, Traitor of Ghet's ability
is not a triggered ability. You
cannot allow your opponent to "miss" it. If your opponent forgets it, you need to remind them, and if that doesn't happen right away you need to call a judge to sort things out.
Yes, I understand it feels terrible, but them's the rules. Blame R&D.