There is no requirement for VFR flights to plan for or carry fuel for a diversion. They do however need to carry a reserve.
Holding for 45 minutes above an airfield is considered enough to have wreckage removed.
Anyone who only does circuits when both the enroute weather etc are suitable for a diversion has never let a student do solo at Vagar!
How many solo students are capable of or briefed for a 50nm diversion after 1 hour solo flying?
Never mkind that - how many instructors get airbourne for a circuit weather check when it may be OK for circuits but absolutely below limits for VFR enroute flight?
Look at the worst case scenario - radio failure and blocked runway?
regards,
DFC