AAR refuelling in helicopters is dangerous, requires high levels of training to get qualified and lot's of hours to stay competent at it. While you are doing that chances are you neglecting another skill that might actually get used more often (unless you have more money, people, resources than you know what to do with). There are helicopter based skills/capabilities that the RAF/UK MOD probably 'should' have, but I really don't see AAR as being one of them.
Being one of the few RAF helicopter pilots who were allowed the opportunity to carry out AAR, it's not necessarily as difficult as some might like to think.