Astronomers were always uncomfortable calling it a planet, because it was so different from the inner eight, but they didn't have a better label for it. Now they do.
This. In astronomy classes, we knew this from way back: it was just a matter of time before it would be extended to formal classification. Because, let's remind it here, classification means nothing except for our ease of use. For its own characteristics, Pluto is better classified as a dwarf planet (even if I think the label is unfortunate) than as a full planet. I really can't understand why some people feel butthurt about it, except for a knee-jerk reaction against "ivory tower academicians" who dared to change a classification that was created by, oh wait,
older ivory tower academicians. It's just too silly.
It's not the odd one out of the planet family anymore, but the archetype for a whole new family of objects which is where all the excitement is in Solar system studies today. So redesignating Pluto is not a "demotion." It's actually the exact opposite. It heralds a step forward in our understanding of and attention to objects like Pluto.
"Better to reign in Hell than serve in Heaven." Very appropriate to Pluto, too.
It's a tenable position, but not the solution to everything you think it is. Rocky planets are, well, rocks. Gas giants are essentially balls of hydrogen: composition-wise, they are more alike stars than other planets. Ice giants have a very hight percentage of water, which would make them
comets in your idea. As you see, it's not easy to find a compromise between competing tugs for completeness and accuracy.
Then we'll change the definition
again. It's not the end of the world. What's up with this resistance to change? This is science, people, not dogma: change is intrinsic to the scientific method. Leaps are made by improving the theory, or discarding it altogether for a better one. We should always strive for the theory that better fit with current data, without letting nostalgia come in the way of accuracy.
You tell us as soon as you complete your PhD in astrophysics.
Those guys make things more complicated than it has to be.
This is exactly as complicated as it needs to be given the current data. If you think you can do a better job, by all means, propose it to the science community and let's talk about it.