This is how languages evolve. If enough people think something about a word, then over time there is a good chance that word will morph into the the new meaning. The same thing happens with pronunciation. For example, originally the "correct" pronunciation of the word "forte" was "fort", however most people think and use "fortay". Now most dictionaries will give both pronunciations or even the "incorrect" one and over time it will almost certainly change into "fortay" completely.
Essentially, „ein Führer” is more than just a leader.
You're not being pedantic, you're introducing an unnecessary element. The etymology of a word isn't relevant in determining its current meaning. Führer is usually translated as leader and there is nothing wrong with that translation.
I am confident other people have different views on this. Fortunately for most people, I don't get to write much on languages. Strangely, while my dyslexia is somewhat preventing this, it is also the same disorder that is causing me to become more obsessive about my writing, including the quotation marks.
Edit: To ensure it, I have reconfigured my keymap to have all the symbols ready as keys.
Example: It's the first thing your mind jumped too although cpeterso never mentioned the Hitler in his comment.
And there is a good reason for that. The surname „Hitler” is an alternative spelling of „Hiedler”. Hitler's father, Alois Schicklgruber, decided to change his name to his stepfather's family name, „Hielder”. Likely because Alois was born out of wedlock and wanted to rid himself of his old surname once he became established. It is unknown why he changed the spelling to „Hitler”.
Adolf Hitler did comment once that he thanked his father for changing the surname, as „heil Schicklgruber” would have sounded awkward.