No. That is not cheating.
The airlines offer something for sale and I buy it. If buying a third ticket makes my entire trip cheaper - it would be illogical for me not to buy it. And whether or not I use it is entirely up to me.
The problem is the airlines are using inefficient and illogical pricing - for a whole host of reasons including incompetency and unwillingness to adapt to a changing marketplace.
> to keep flying some-what affordable to everyone.
Saying this keeps flying affordable for all is a "feel-good" argument - it has no substance.