Why is this amazing, (except maybe you are amazed at the strength of the evo case as illustrated by the URL I gave you and the weakness of the creato case)? Difficulty in classifying transitionals is a prediction of ToE, which is why it is so interesting that the creato scientists cannot agree on the classification of fossil hominids. If we could classify everything easily it would be a falsification of ToE!
If you understood real science, you wouldn't even be asking this question. A common, universal definition of your units of measure is absolutely essential and foundational to any science. Since evolution describes speciation, it is absolutely essential that a mathematically precise definition of species and species identification exist. Otherwise it is impossible to create experiments to test the theory.