Sadly, some don't regard the customer's experience as important to the continued long term success of a business. Anyone saying all airlines follow the Allegiant methodology hasn't flown much as a paying passenger on different airlines and seen how they handle it when a flight is cancelled.

When a flight is cancelled most airlines will try their best to put passengers on their next available flight that day, or even on a competitor's flight to get them on their way. Those airlines reciprocate this act of goodwill with one another, knowing it helps to make the entire flying experience better for the customers, believing that they may lose something today but will gain in the long run.

Since Allegiant often only has one flight a day from a given airport that first option isn't available, and as for the second option, they never, ever book a passenger on another airline. So people usually lose a day of travel, missing important planned events, or have to buy a last-minute ticket with another airline which is not reimbursed. That's the reason travel agents do not recommend Allegiant to business travelers, you can't rely on getting to your destination on time. Allegiant will tell you that they are for the leisure traveler whose time is flexible, but even a family going to Disney World has made plans and wants to get there on time. When you buy a ticket on a low-cost airline you expect some compromises, but getting to your destination reasonably close to the scheduled time is expected by all.