The very reason for having a definition of "planet" is political: what to put on science books for primary schools. Scientists don't need a definition or a list: students do.
Well, that's not entirely true. The idea behind the 2006 IAU conference was to finally come up with a real scientific definition for the term "planet," one that would be based on meaningful physical parameters rather than historical convention and that would be useful as a classification for scientists. I don't think they succeeded very well at meeting those goals, because the decision-making process was rushed and ultimately the result of compromise rather than scientific consensus, but it's incorrect to say that they weren't even trying
to come up with a scientific definition, because that was the entire purpose of the exercise.