Table Change allows ratholing?

[ungarop]

Playing 2/3 NL (100-300 buyin) at Oceans 11. First time at this card room, although I have been to other card rooms in California (Bay 101, Commerce, Bike).

Super LAG comes to the table, buys in for 200 and proceeds to run it up to 1000+ in about an hour. He's raising every hand to 10 preflop, calling reraises, betting every street and hitting 2 pair or better every hand.

Immediately after he wins the hand that puts him over 1K, he asks the brush for a table change to another 2/3 game.

15 minutes later he is called, goes to the cashier with his two racks of red, cashes out, and then buys into the other 2/3 game for 200.

I just don't understand a card room rule that would allow a player to do this when changing tables at the same limit. I can understand the rule when buying into a different limit (like only being able to bring the max to the next highest limit NL game for instance).

I guess I never noticed this at Bay 101, Commerce or the Bike if it happens there since I am not a regular. I am pretty sure this does not happen in Vegas either. At Foxwoods where I play, I believe the rule is that you bring the entire stack.

Can someone explain why this is a good rule for the players or the room?