Geico says can't drop a driver if lives in same household

We're a 2 parent single child family. My son is 19 and on our car insurance. I'm a 45 yr old male with a few claims on my driving record. I was going to get my own car insurance but our current policyholder, Geico, told my wife I couldn't be dropped from our current policy since I'm in the same household. I say shenanigans!! Any thoughts?