So if I choose to disagree with you, I'm stupid. You fire insults at me, and you ACTUALLY expect me to adopt your opinion because of it. How utterly pathetic.
Grendelsbayne is being a bit harsh maybe but this isn't his\her opinion we're talking about, but rather a scientific definition. Which has changed, and may do so again in the future as we accumulate more knowledge.
After all, "planet" used to just mean a light in the sky that moved against the fixed background of the other lights, back before we had any comprehension of what these objects were.