effect of NMS

In some casinos if you drop from 2 hands to 1 in blackjack, you cannot go back to 2 hands until the next shuffle (called NMS in Current BJ News). What is the (negative) effect of this rule?

I understand the No Mid Shoe entry rules are partially designed to discourage counting teams from sending in a Big Spender when someone at the table who is making minimum bets and counting cards gives a signal. I think its also a rule that allows a semblance of power (my table, my cards) to the existing player similar to the fashion in which table limits will be raised for a desired player to discourage others from sitting at that table.

As to mathematical effect on the edge, I doubt it has any.

For me personally, it's a little of the "my shoe" mentality, but it's a lot more of the flow. We waited for the shuffle, we have a rhythm going, and someone dances over and stops the game for "Cash, $300!...," Which the pit boss invariably doesn't hear for a while. "Three HUNDRED!" as we continue to wait. The pit boss was in the middle of a joke with another dealer, and comes over laughing. "OK...OK...three hundred..." Chips are finally given, and sit in front of the new player, who forgets to bet, and says "wait, wait!" I don't mind all of that happening, but can it happen betwen shoes, rather than right in the middle of the deck?