Your argument only works for catastrophic insurance.
In practice, people take out insurance even for events that would not put them out of business.
Btw, if you are talking about 'value-generating enterprises', ie businesses as buyers of insurance, then your argument doesn't really work either, or at least not without caveats:
When a business suddenly has a large liability, and it goes bankrupt, all that happens is that the equity owners are wiped out and the creditors take over. The underlying business can and often does continue uninterrupted, and has approximately the same value as a going concern as before.
Also, being able to run as a going concern is of finite value to a business. If your business can take a 51% chance of either doubling in value or alternatively going bust, then that _might_ be a good gamble to take if your shareholders are well-diversified. For example, if index funds are your main shareholders.
Humans need considerable better odds before they consider such a gamble. But people do regularly put their life on the line in return for very finite benefits. Eg every time you leave the house, and drive a car. Or even more stark, any time people conveniently 'forget' to put their seatbelts on.