[jimworcs]

Most low costs in Europe do not do this... each segment is treated as a one way contract. Cancelling or no showing for the outbound does not impact the return. Even the world's most anti customer airline, Ryanair, doesn't do it.

The reason the high cost legacy carriers do it is because their pricing model is ridiculous and byzantine. It was often cheaper to buy tickets and "skip" a segment. Airlines manipulated pricing to exploit customers.. when customers used the system to their advantage, suddenly that was unacceptable and the practice was effectively banned by this policy of cancelling future segments. It is just one more anti-customer policy which is defended for no legitimate reason. It is the equivalent of me buying two boxes of cornflakes at Walmart for the price of one. I then give one away to another customer. Could Walmart then charge me for the second box, because they "lost revenue" when I gave it to another potential customer? No, because that would be ridiculous. Only in the looney world of airlines does this make sense (and for the small minority of employees and apologists who frequent this board).