It's just one way of doing things. Some voltage regulators simply remove the field voltage in a case of over voltage, but you've often got to cycle the breaker to reset it, so in practice it is no different.
At least with the crowbar circuit, you'll see the tripped breaker when you investigate the fact that you are no longer charging.
I don't see how it is dangerous particularly? After all, a flat battery is probably better than one that has been boiled by over voltage, and your avionics shutting down because the battery has started running down is better than them being permanently fried!