"So much 'intellectual' debate and all in vain."

In vain for you.
I find it helpful to *try* to gain a reasonably clear perspective on this stuff.

You'll be saying next what a waste of time indeces for libraries are, after all they're all just "books". I like a bit of ancient Greek drama now and then. It's labelled 'ancient' because it was popular during a particular period in history - and that label makes it easier to find a copy of what might interest me (now and then), over say, something written last week.

So no, definitions are not in vain, they are pragmatic and useful ways of organising vast swathes of stuff, for those of us that are interested.