It's implied. Masks are an extremely simple thing, and you're suggesting that masks can't be tested because people can't figure it out, instead of blaming the masks themselves for not being effective or easy to apply. We call people who can't figure out simple things stupid (though perhaps not to their faces lol). I don't believe people who don't wear masks "properly" are uneducated. They don't care, because they know that the whole ritual is pointless. They don't care to fight it, and just want to conform the minimum amount to be left alone.