I already wrote my whole answer after reading the questions, but only after did I read the rest saying it's not what you want to hear, so I deleted it. Hope somebody will give you the answer that may not be realistic but is what you want to hear.
[removed]
I already wrote my whole answer after reading the questions, but only after did I read the rest saying it's not what you want to hear, so I deleted it. Hope somebody will give you the answer that may not be realistic but is what you want to hear.
legitimate reason
If 'legitimate reason' is down to the airline cancelling the flight, then yes, although you'd need to ask at time of cancellation to see if your rebooking can be deferred.
If 'legitimate reason' is down to the passenger just wanting to have a jolly for a few days, then no.
Airlines are private businesses. Each can be different. Airlines are not a monolith. The only requirement is to take passengers to the final destination on their ticket. Everything else varies.