The title is not misleading if taken in the pure economic sense. I get your point. Imagine if the government decreed that all citizens were to dig a hole ten feet deep and then simply fill it up after that, there would be little "cost" in terms of a government department, but a significant cost to the citizenry in terms of productivity and GDP.
Even with people who do not have a paid job for a living, if they spent X million hours collectively filing tax returns, that is an opportunity cost to do other things that would either be more productive or would at least be of value in terms of pleasure.
This tax code will NEVER be simplified. Too many interest groups. A pipe dream - would even Republicans dare take on say homeowners?