Andrew Gimson mourns it:
The idea of a gentleman was a more inclusive one than it sounds to modern ears. One of its greatest advantages was that you could define it so as to include yourself. You could behave like a gentleman, without possessing any of the social attributes which a gentleman might have: there was no need to possess a coat of arms, or a country estate, or engage in field sports, or wear evening dress. At least since Chaucer’s time, there had been a distinction between the social meaning of the word, and the moral. It was evident that well-born people, who ought to know how to behave like gentlemen, did not always do so, while others sometimes did.
The Dish 