Perhaps a different culture between string players and brass players? Or maybe just different parts of the world? Eastern US here. I play trumpet and from the earliest years was heavily encouraged by all band directors and conductors to tap my foot at all times. No conductor ever corrected the practice later or pointed it out as an error, but I often heard the advice repeated for everyone to do it. Maybe they viewed it as a necessary evil though, like in Mr Holland's opus when when he is beating the tempo into the guy's head with a mallet while he wears a football helmet.
