Planets predate modern astronomy. You have to negotiate with the public if you want to change what “planet” means. To most people, in most contexts, it means 8 or 9 specific things that they have specific ideas about, not a theoretical category of infinite objects.
Few things sound more like more science than "planets". Telling people "Well actually 'planet' isn't a scientific term, it's a historical / cultural term" will also significantly reduce their trust and interest in science.
> Planets predate modern astronomy.
If we're segmenting off "modern astronomy" then Pluto wasn't even discovered yet.
And we discovered Ceres long before Pluto. It would be pretty rude to keep excluding Ceres just because we knew about the asteroid belt before we knew about the Kuiper belt.