Why Should We Care Where the Markets Are Efficient?

The claim from efficient markets theory is that you're wasting your time. Why should we care where the markets are efficient or not? It matters for society more broadly because even assets underpriced incentives are created to neglect or abuse it. Australia is learning this at the moment with a huge glut of compromised apartments being thrown off around Sydney and Melbourne. A lot of them have structural damage or building problems. And I thought you know this whole story about efficient markets that attributes all of the movements in the stock market to new information. It just isn't right. It's something, maybe it's new information about the folly of some investors but it's not new information of the kind envisioned by efficient markets theorists