A good theory in sociology would be very practical, I assume. It would help you to understand how societies behave, how people make decisions. That problem is too complicated. Nobody knows how to do that.
In about 1970, I decided I was an engineer. I continued to do work that was almost entirely mathematical, but I realized I was interested in building things, and that made me an engineer!
It was a bizarre business at the time, you could be working on cryptographic projects for the government, still they wouldn't tell you anything about what they wanted you to do.W