When I wrote a small blackjack program some time ago, I had to put some upper limit on the allowed number of splits to prevent it from running out of cards. Even though a typical hand consists of only two or three cards, the (theoretical) maximum (the ("good") programmer has to consider) can be dramatically high if you allow unlimited splitting. (For example, one person may need 32 cards or more in single deck games: If a player gets 16 tens and split them and if he hits twice on every split hand, then he alone will use 48(!) cards.)
I suspect that the casino imposes a similar restrction for the same reason...
~Black Jack in the Box.