Maze1125 said:
Yes, mathematics and science benefit hugely from precise and universally agreed definitions (although in this case, the benefit is in fact minimal) but that doesn't make the definitions objective, just agreed upon.
The borders between the definitions are subjective from the point of view of the ruling body for those definitions.
However, the actual catagorization within those definitions are objective, which was the entire reason for the alteration of those definitions.
Suggesting that subjectivity of the definitions from the point of view of the ruling body extends to say that classifications within those definitions are subjective is a fallacy.
The very reason the definitions -were- changed was so that designations of certain bodies would no longer be subjective, but they could be classified objectively.
Previous to then, Pluto was a planet because of subjective definition. However, the discovery of Eris turned that definition on its ear and challenged the scientific community to come up with a system of designations that -was- objective.
Essentially, they either had to come up with a designation that fit the current system, or abandon it and start again. They chose the latter, and they had their reasons for doing so. Expert reasons that one versed in the field can understand, and present a valid and relevant opinion on.
Outside of that field, however, you could state that the subjectivity of the objections means you can form your own opinion, and you can. However without the benefit of that valid and relevant reasoning, your opinion is not informed.
So, yes, you can have an ignorant opinion that Pluto is a planet. Or you can present a valid and relevant argument as to why it should be. And 'Grandfather clause' doesn't exist in serious scientific endevours, so good luck with that.