There is no particular reason for me to think casual app-based renters will ever learn this etiquette, especially given the high tourist density in SF.
And regardless, if etiquette is needed for safe and effective sharing of the sidewalks, it's up to these scooter companies to make sure that etiquette training happens before they accept money and turn somebody loose. Otherwise it's classic "privatize the gains and socialize the losses" foolishness.