> How is buying insurance on things you expect to fail any different than, say, buying options on the stock market, or some other form of intelligent betting?

Insurance, unlike options on equity stock or indexes, require an insurable interest. The pricing of insurance assumes that the buyer of insurance would rather not use the insurance policy; the options contract on stock makes no such stipulation. They are a bit similar in practice but both are structured, regulated contracts and are defined differently.

This lady did not have an "insurable interest" in the flights she was purchasing insurance on, since she did not actually intend to go on on the flight (she bought the insurance to profit from the insurance). Had she bought an "option" and not "insurance" on the flight, fraud maybe would not be in play. However, expect an "option" to be priced differently.