That's a pretty condescending thing to say. To answer your rhetorical question, we are taught from elementary school to say, "x = 3", not "3 = x". Yes, it's the same, but it's jarring.
I remember getting marked off once in either my algebra 1 or geometry class for leaving some answers in the form "3 = x". (What, you gave me an equation of "5 = 3x - 4"! It's harder to follow the work you make me do if I suddenly swap everything.) Anyway, I never found it jarring, though I can see why others might. (And if you've never had exposure to TI basic.. 3->x.)