Terry Pratchett: Doctor Who isn't science fiction

Writing in SFX Terry Pratchett explains why Doctor Who,
whatever its other merits, isn't very good science fiction. A provocative hypothesis,
but it's hard to argue with his reasoning:

The unexpected, unadvertised solution which kisses it all better is known as a deus ex machina – literally, a god from the machine. And a god from the machine is what the Doctor now is. A decent detective story provides you with enough tantalising information to allow you to make a stab at a solution before the famous detective struts his stuff in the library. Doctor Who replaces this with speed, fast talking, and what appears to be that wonderful element "makeitupasyougalongeum". I don't know about you, but I don't think I would dare try to jump-start a spaceship that looks like the Titanic by diving it into the atmosphere… but I have to forgive the Doctor that, because it was hilariously funny.

People say Doctor Who is science fiction. At least people who don't know what science fiction is, say that Doctor Who is science fiction. Star Trek approaches science fiction. The horribly titled Star Cops which ran all too briefly on the BBC in the 1980s was the genuine pure quill of science fiction, unbelievable in some aspects but nevertheless pretty much about the possible. Indeed, several of its episodes relied on the laws of physics for their effect (I'm particularly thinking of the episode "Conversations With The Dead"). It had a following, but never caught on in a big way. It was clever, and well thought out. Doctor Who on the other hand had an episode wherein people's surplus body fat turns into little waddling creatures. I'm not sure how old you have to be to come up with an idea like that. The Doctor himself has in recent years been built up into an amalgam of Mother Teresa, Jesus Christ (I laughed my socks off during the Titanic episode when two golden angels lifted the Doctor heavenwards) and Tinkerbell. There is nothing he doesn't know, and nothing he can't do. He is now becoming God, given that the position is vacant. Earth is protected, we are told, and not by Torchwood, who are human and therefore not very competent. Perhaps they should start transmitting the programme on Sundays.