Even low traffic airports with iaps require full ATC in the UK. In some parts of Scotland for instance, airports such as Islay might only have one scheduled IFR arrival per day, but they still have to have ATC, basically because if a second aircraft turns up unnanounced and also wants to fly the iap, only an ATCO can provide the necessary instructions to separate them.
Not forgetting of course, that the CAA have a mandate to require the aerodrome authority to provide a certain level of ATS (ATC, FIS or A/G) depending how complex they decide the traffic situation might become at any time.
Thinks: What makes me suspect bad bear and Fuzzy 6898 are the same person?