Taxonomies should be emergent and asynchronous
Having to define taxonomies up front creates a blocking issue before we are in a position to solve it. Awareness of where a thought fits within our existing taxonomies, or indeed whether it opens up a new one often comes much later than the thought itself. Any system that prevents or discourages the user from classifying their thinking asynchronously and after the fact, and needlessly forces them to do this work up front will substantially constrain the emergent properties that digitally-augmented thinking is best placed to support.
Curation should be considered not forced. By resisting the urge to heavily classify at creation time, we permit connections and structure to emerge over time and solidify a habit of incremental improvement of our notes and thinking.