Can you give an example of how a lack of consideration of extensibility might come back to bite one?
And please not a contrived straw man example that is obvious to everyone reading, something that one might legitimately do in the real world for reasons of simplicity and expediency, that could turn out to be a genuinely painful experience when it becomes necessary to extend. (Obviously I don't expect an essay, but I'd appreciate if you could try to give us an idea in a reasonable amount of text.)
And please not a contrived straw man example that is obvious to everyone reading, something that one might legitimately do in the real world for reasons of simplicity and expediency, that could turn out to be a genuinely painful experience when it becomes necessary to extend. (Obviously I don't expect an essay, but I'd appreciate if you could try to give us an idea in a reasonable amount of text.)