What casino does not allow you to hit a soft or a hard 21 for that matter? Are you saying the casino has rules to keep you from inadvertently losing. Nay. Nay. It is not the casino's business what your goals may happen to be, nor is it in their best interest.
If the dealer inadvertently flashes the next card to be dealt, a ten, and I have sixteen, I am still allowed to hit. The casino will not advise me that I am asking for a certain bust card, although a sympathetic dealer might of his or her own accord.
I defy anyone to find a casino that will not allow a person to hit a soft 21. I'm not saying they will allow doubling down on a soft 21, but that's a different issue-- the casino might have something to lose in that case. I'm talking about a simple hit on a soft 21. This will be one for the eleven o'clock news, if you can find it.
Further, the rules say that I have either eleven or twenty-one, depending on how I wish to play one of my aces. If I choose to value my hand as an eleven, the casino cannot stop me. Who knows, my second hand may be a 5/6 double down for $10,000. My sixth sense might tell me to take a hit on my $25 hand, since I sense another ace is coming.
I do, however, wonder if they can force me to stop hitting when I get to a hard 21. It depends on how the rule is stated. "The player may hit until he has received more than 21", is my guess, but it could be, "The player may hit until he has received 21 or more", in which case the dealer would move to the next player once you have reached 21. Anyone know? I wonder if it varies? It is a silly issue anyway, except in the case where a ploppy accidentally calls for a hit when they already have 21. It could save them some money if the rules requires the dealer to stop at 21.