So what's the solution? Complex theories sometimes do a better job of explaining reality than simple ones, but these theories are way beyond the mathematical skill of most undergrad econ majors. A better alternative is to start teaching empirics in 101.
Current textbooks, including Mankiw's, almost all play down the role of data and evidence. They sometimes refer to the results of empirical studies, but they don't give students an in-depth understanding of how those studies worked. Yet this wouldn't be very hard to do. The kind of empirical analysis now taking over the econ profession -- often called the "quasi- experimental" approach -- isn't that hard to understand. Simple examples could even be done in the classroom, or as homework assignments.
In other words, the economics profession has gotten real, and it's time for Econ 101 to do the same. We now have an academic economics profession focused on examining evidence and an Econ 101 curriculum that focuses on telling pleasant but often useless fables. Econ education needs to get with the times.