Which is not saying that the people making these scarves are getting rich. I've seen the scarves sell for about a hundred dollars. Even if you have a machine to do a lot of the work, for the most part a knitting machine isn't something that you push a few buttons and then go to lunch and come back to find a completed scarf. So even if you have a machine you still spend a lot of time on it. And of course yarn isn't free either. If I wanted to sell a scarf, and I wanted to make a reasonable ten dollars an hour for my time, I would need to sell the scarves for at least $175. (That's for season 12. Other seasons are longer or more complicated and would cost more.) So I figure that the people who sell the scarves on eBay are a bit better at this than I am, but they are still working for about five dollars an hour.
Anyway, while there are copyright laws and all of that, and the BBC probably has the legal right to make someone stop selling things that came from the show, and they might even have the right to ask someone to stop telling people how to make their own toys and/or costumes, for the most part you're supposed to know not to enforce this particular right on fans who are not getting rich from knitting and who are not in direct competition with anything they are selling. Fan made stuff is free advertising, so the fans are usually left alone.
All of this was almost two months ago, and the Doctor Who Scarf website is still there, so I'm guessing that they are not going to do anything about it.