There are even cases of retrenchment on positive space benefits.

For example, on AC if an employee uses and ID80 (80% discount) positive space benefit to fly a heavy route (say YYZ-HKG or YYZ-LHR), the employee will be restricted to ticketing in an economy fare. The employee then buys 2 MCO's, one to upgrade the entire ticket to YID80 plus a one way J upgrade, and the other for the return J upgrade.

IF there is space 48 hours before departure, they can be confirmed in J, and they surrender the first MCO. If there is space 48 hours ahead of the return, they can then confirm that.

Notice that this is for revenue (discounted) positive-space travel in J. This is an employee benefit, which employees take into account when deciding whether their contracts provide fair compensation. Most FA's, reservation agents and clerical staff are notoriously underpaid, relying on benefits to make the deal worthwhile. Then after 5, 10, or 30 years with the company, the rules start to change and the benefits are watered down without improvement in the salary package.

Any good manager will tell you you have to keep both your customers AND your employees happy. It is much cheaper for the airline to give generous travel benefits to its employees than to pay them what they could earn in jobs in other industries.

For my part, I never feel that I have gotten less than what I paid for when I sit in the class I have booked. And I do not begrudge the employee who is either using hard-earned benefits, or is working to get from A to B.