@ 2_sheds: thanks for your patience, I am afraid I am handicapped with a literal mind... To me a "controller" is a person exerting "control" iow someone with authority. When I took ground class, and subsequently the then separate R/T course, I was told again and again that there is a strict distinction between "control" and "service". It seems this distinction is less firm, to say the least, in the UK. That may work (more or less) for those used to it, but I still fail to see the reason why, and I must admit it annoys me beyond reason. Is there any reason to call a "chair" a "table"? Why then call a FIS operator a controller?
On second thought, the rationale seems to be the creation of a very "soft" transition from "controlled" to "non-controlled". Laudable as that concept may be, most continental FIR's have gone the other way. My own EBBU FIR for one example only has classes A, D and G; and there is no way the (one and single) FIS operator of Belgian class G would even begin to suggest one should head so much or descend to such or such. The furthest I ever heard them go was "xx-xxx, you are about to enter EByy airspace, change to EByy tower at abc.de". And that works fairly well, in a difficult and busy airspace we have no more than the usual share of midairs and other airproxes.
One sticks to what one is used to, I suppose. Which is another reason for me to avoid those queer Brits and their funny bits of airspace, begging your pardon. Vivat Brexit! Splendid isolation!