>If someone will lend you money without cross-collateralization, why wouldn't you prefer that?

I would prefer that! I'd prefer even more strongly that the debt be owed by someone else entirely, so a default isn't associated with me at all. If you're up for it I'd also prefer to use your credit card number to buy stuff on Amazon. But for whatever reason the law doesn't always seem to follow my preference.

I'm sensitive to your point about restricting formation of new corps. The system can't just be changed randomly without extremely careful thought. And often not even then.