I must disagree here. First, it isn’t the TSA’s purpose to police the size of the bags. Nor is it their function to make any determination as to who is “inconsiderate” or “ill-prepared”. And c'mon... the idea that any airline would do something so imbecilic as to what I guess you’d call “teaching them a lesson” would amount to business suicide for that airline. Remember that passengers are also customers; they aren’t there to be punished or be taught a lesson.
The size is so much, over that it should be TSA enforced that the bag won't even be allowed to pass the security check. Let the inconsiderate or ill-prepared carry their own bag back to the ticket counter and check it. I bet that will only happen once and they will have gotten the message. Flights will be missed as a result, but the message will get out.