My 2c is that if the majority of people are confused about the purpose of a punctuation mark or language feature in general, then that feature is not actually fulfilling a useful function. If it was actually useful then people wouldn’t be confused, they would just be using it. People would learn it organically and not need it to be explained.

That example sentence would function exactly the same if it was separated by a period, nothing is gained by using a semicolon. No new information is added, you are just going to make people wonder why there is a semicolon there making the sentence less comprehensible.

Its sorta related to the prescriptivism vs descriptivism distinction.