I've always struggled to understand why, in regular BJ, 'even money' is treated as a separate entity to the equivalent insurance bet, but I think this thread has helped me understand.
The casino would like players to take insurance all the time, since it favours the house. A player who might otherwise be tempted to take insurance can't do so if he doesn't have the funds to cover the bet. However, if the player has a BJ then the house can 'kindly' offer to roll up the whole transaction into a single, even money proposition.
Is that about the size of it?