I think some people freaked out at the idea of our tidy little system being filled with maybe 15 planets.
It was silly to yank it from Pluto because it’s too small seeing that we have systems with worlds 4 times Jupiter’s size, orbiting half the distance of the Sun to Mercury in 10 hours.
Planets come in so many styles, it is dumb to limit it just yet.
Pluto was never a planet. Pluto is an asteroid. It was called a planet because it appeared close to where Lowell was looking for Planet X, the previously unknown planet that likely exists but hasn't yet been discovered.
Having a couple of small asteroids orbiting each other doesn't make them moons, nor does it qualify the largest one of them to be a planets.
Interestingly, Pluto's orbit around the sun is an ellipse which brings it closer to the Sun than Neptune at perihelion, and twice as far from the Sun as Neptune at aphelion.
And, speaking of tidy, there is somewhat of a correlation of distance from one planet to the next. Take the orbit of the planet, multiply by 1.6 and you will get very close to the orbit of the next planet. For instance, Earth, 93 million miles, times 1.6 equals about 147 million, which is fairly close to Mars' orbit of 141 million miles. The pattern holds out all the way to Neptune, with the asteroid belt at 1.6 times 141, or 225 million miles. It is not exact, and the actual results may vary, but it is still interesting to note the interval. Pluto does not follow that pattern.
If it was only fifteen or so, the decision might have been different but there are probably at least a hundred objects around the size of Pluto in the Kuiper belt and possibly considerably more - we've only found a few of them so far because they are hard to find from Earth, but there a lot of them. The odds of there being more than one or two "planet sized objects" anywhere remotely close to the sun however are very low as the effects of their gravity would be detectable - there is a reasonable possibility of one more Mars size planet at about twice the distance of Neptune, or a gas giant much much further away as that could explain some irregularities in a couple of the dwarf planet orbits - but there really can't be much more than that on current understandings of orbits.
Pluto, sizewise, is simply of a category that is much more common than the planets. Include Pluto, and you're going to have to include hundreds of others eventually as we find them.
The only grounds for keeping Pluto really would be to grandfather it in as a special case - which I wouldn't mind at all, and some astronomers do support that idea - but it would be special treatment for historical/nostalgic reasons.