Such a strongly worded rebuke is hardly called for. The original poster was not expressing a legal opinion, but rather his/her opinion that the terms of this particular offer are unfair.

I happen to think the the terms are neiter fraudulent (in the legal sense) nor unfair. The poster merely makes a rational economic decision not to upgrade the available fares if the cost to do so exceeds the value to him/her of the free ticket. However, there are many other travelers who will earn the free ticket without purchasing more expensive tickets than they otherwise would: business travelers, for example, who do not qualify for the deeply discounted fares to which the promotion does not apply. And it is, after all, these flyers who the airlines are trying to attract.