> Classifications are useful.

I wasn't arguing against classification, just that I remain unconvinced that the classification which IAU adopted is superior to the alternatives.

One problem with the IAU definition: it only works for our planetary system, not for exoplanets – with the end result that we have two different definitions of "planet", one for our system, one for everywhere else.

Now, of course, that in part reflects that we have vastly more information about our own system than any other – but, a few centuries or millennia from now, I expect we'll know a lot more about some of those other systems – we will probably have sent probes to explore the nearer ones by then – at which point people (or AIs?) will probably push to unify the two definitions. My own bet is they'll be more likely to unify them by dropping "clear the neighbourhood" from the our-system definition than extending it to apply to other systems. Splitting the common category of "planet" into two subcategories based on "does it clear its neighbourhood" works much better than insisting on two disjoint categories based on that criterion when you have very limited information on where that criterion is met.