Not all classification schemes are subjective. Consider the Periodic Table of the Elements that you learned in your high school chemistry class. The only difference from modern tables is that it peters out at element 103. Modern tables contain a few more unstable elements that have to be produced in a laboratory, and barely last long enough to detect or measure. Except for the addition of newly discovered elements, it has not changed since Dimitri Mendeleyev conceived it in 1869.
Chemists don t argue about where to put newly discovered elements in it.
That is because the Periodic Table is objective, rational, and scientific. It isn t driven by the prevailing whim. On the other hand, the biological classification system is constantly being revised. That s because it is subjective. It is governed by opinion, ego, emotion, pride, and nationalism.