Not only do I think Pluto is a planet but I think the Pluto and Charon are double planets. Hear me out. Earth/Moon is a planet and moon because the Earth/Moon system orbits around a barycenter (the point around which both bodies orbit) that is contained within the planet. Earth orbits around the Sun and the Moon orbits around the earth. Same with all the other planet/moon systems in the solar system. Except for Pluto and Charon. Their barycenter is outside both bodies. This makes them a double planet system.
As to why they are planets, they are spherical bodies that orbit the sun. That definition makes them planets. Simple and non-arbitrary.
PS This would also make Ceres a planet and I’m okay with that.