Even if this is true, most people don't know how boring their taxes are until someone tells them. So the argument is that by making it easier to falsely believe

Even if this is true, most people don't know how boring their taxes are until someone tells them. So the argument is that by making it easier to falsely believe no special cases apply to them, more people will file their taxes incorrectly. You might predict otherwise, or you might think the cost is outweighed by the benefit to the people who really do have boring taxes. But I think the argument makes sense.