I see this all the time in our Saturday 8-ball tournament. Ordinarily, the guys only split when neither one of them is "certain" that they could win the final match. If one player is playing strong and wants to play it out, then they play it out.
It is your call as to whether or not you split. If you want to play for it, play for it. No one should hold that against you, and if they do, f-em. You play the tourny to win.
As for the folks in the calcutta, yes, it is somewhat unfair to them to see a split, but only for the guy who had the sure winner (if there was one). In the end, the calcutta has nothing to do with the playing of the tournament.
Joe