I am sympathetic, to a point - mainly because it is possible to improve interfaces, there's no physical constraint preventing that (there's also no guarantee that a different interface will work equally well for all users, of course). But I also would suggest it's reasonable to expect a certain level of basic understanding. Imagine someone pumping gas into their radiator, because the two holes were the same size. We don't design cars to prevent that, but we also don't expect people to make that mistake.