The great British Sci-fi drought

As the only piece of new British Sci-fi available for free nears it's ending I ask: Why has British TV got so few fantasy and sci-fi shows?
Humans has only got two more episodes to go, and once it's done then I enter the long wait to September 19th, when Doctor who series 9 airs. That's  nearly two months without a single original piece of sci-fi broadcasting (That I know of.). This isn't really a problem for me, as I have two series of Star trek and thirty episodes of classic Doctor who to watch, but the problem is worse for many.
Right now America has loads of sci-fi/ fantasy programming on (Probably because it's 40 times larger than the UK.), which only makes me more annoyed. While they have hundreds of different series in every genre we have maybe one or two on at once.
It's not like sci-fi gets bad viewing figures. As I've already written before 'Humans' has gotten the highest ever viewing figures for Channel 4, and every episode of Doctor who gets into the top twenty of the weekly viewing figures. Fantasy programs like 'Game of Thrones' are some of the most watched dramas of all time. So why aren't there more of them?
The obvious argument is that they cost too much to have them constantly rolling out. But I don't see why something like 'Humans' or Doctor who episodes like 'Listen' and 'Blink' would have higher budgets than one of the endless crime dramas that pop up. I think the problem is a lack of good sci-fi ideas and writers. The reason there aren't enough of these? Because there isn't enough sci-fi on TV for people to see writing TV sci-fi as a real job. Damn.