"...only mathematical expectation matters."
Well, maybe not.
Suppose you are on a gambling ship with fair to good conditions. It's crowded and if you give up your seat you'll never get another;ergo, you can't bail out and reseat yourself for a fresh shuffle. You'll just have to play a straight bet variation game in the same seat for 4� hours. The table minimum is $10 and the maximum $500. You may never be able to spread to two hands.
Consider that if you play with optimum mathematical advantage in your departures, you may draw more attention to yourself. It's bad enough your bet is usually two reds, but sometimes a small stack of black. You don't want the donkeys piping up to the floor when you hit 12 against small cards or 13 against a duece.
As Lawrence Revere had observed, "Sometimes your disadvantage is greater than your advantage." For those who never understood his statement, he meant that it is sometimes wise to forego an element of advantage if it reduced the risk of lifting the veil.