Co-blogger Bryan has done an admirable job of critiquing "economath" here and here.
What follows from his critique is what I call "the tragedy of economath." Over my 30+ years of teaching mainly Masters students, I come across really good students who "get the economics bug." They see the power of economics to explain things in the world and they often finding economics dramatically changing their view of the world: which policies are good, which economic actors are the villains and which are the heroes, etc.
A substantial fraction of those students--say 15%--say they would love to go on and get a Ph.D. in economics and teach. Given that they are Masters students who can get the GI Bill after they retire, such a strategy is highly plausible. Except for one little detail. It's often expressed as follows: "I can't hack the math." It's not that they're typically mathematically illiterate. The most advanced math tool I use in class is algebra and the students I'm talking about have little or no problem with algebra. It's just that many of them have looked a little into Ph.D. programs and they know that what is required in those programs goes way beyond algebra.
That means that we're missing having a substantial number of people like that as future colleagues and teachers. And who replaces them? In many cases, people who have much less understanding of economics but who are good at math. This is a tragedy.