LFittNI
I think you have by now got a representative answer to your question. Seems to me that on the whole those who are not entitled by regulations to do it resent those who are entitled doing it. And I certainly don't think the practise is becoming more common; quite the reverse. The public are becoming less aware of what retired service personnel are like and can do.
Unfortunately, by mocking those who do, you and the other cynics are perpetuating the civilian stereotype of retired senior officers as incompetent blimps. After 34 years in the military I can safely say that, though I know some four letter men who were promoted above their ceiling of competence, I do not know any blimps from any service. You do yourself (presuming you are ex-military) no favours in perpetuating this image. Be proud of what we in the British military are and were. I am.