It's fantasy, not science fiction
Dr Who never has abided by the constraints of the science fiction genre, which makes it fantasy, or perhaps (given the epic scale of some episodes) space opera. So to criticise it for not being SF is as pointless as criticising a screwdriver for not being a hammer, IMHO - they're two different things. What Dr Who has been, when at its best, is cracking good drama. I gave up on this series after the second episode simply because the writing was such utter drivel, which the excellent acting had no hope of being able to retrieve. It would be nice to see Mr Capaldi have some good scripts to work with, but until I hear that the scripts have improved, I'm staying away.
And if you happen to like the current series just as it is - good for you! I'll not be back until it's more to my tastes though.