This is a good example of making the mistake of conflating implementation details and user interface design. Firefox always had two boxes: URL bar and search. One of the big changes Chrome made when it was born was to have the Omnibar, being of course one bar that does both. If you think about this as an engineer, Firefox's design decision makes sense. You don't want to accidentally leak things to a search engine. UR…
I don't think good software always aims for the lowest common denominator. It's not an unequivocal good that users' lack of education is catered to. Infantilizing users makes them more dependent on services, and less able to navigate the internet.