But getting the basics of Graphical Design can still help both appreciate a good design and "understand" why "that stuff" feels ugly, and being able to discuss with a graphic designer and talk the "same language"
Same thing with "Programming". No one claims that 100% of the population should understand Rust borrow checker or functional purity
But everyone should understand (and be able to copy-paste some code and "fix" it until it works) the concept of a sequence of instruction, a loop to generate repetitive stuff, the concept of variable (and therefore template and mail merge), a if (and therefore be able to do basic stuff in Excel). So they can talk to engineer and get what they way. And maybe everyone should be able to do FizzBuzz or display the number from 50 to 1 with a loop going from 0 to 49. At least in pseudo-code.