I've never liked any of the Doctor Who spin-offs and I don't understand them conceptually. The only thing that the show has ever positioned as being important is the Doctor, and whoever his companion is at the time. And given the nature of the show, there isn't the sort of cohesion that lends itself to the kind of franchise RTD wants it to be. It's too big and too random, with no internal consistency. And it's also the kind of show where the spin-offs would be subordinate to the main show. With Star Trek for instance, each spin-off stands equal to the others. I can't see that happening here, which makes you wonder why bother?

Alllllllllll that being said, if one of the spin-offs is a show called Master What about the Master and his companions flying around time and space starting shit, I would be very into that.