Is there any good reason for NOT calling?
Exactly my view. Whether it's just the hour round trip burger run, or a full nav across half of the UK, there's no good reason not to take a few mins before the flight to call the airfield. They will have much more accurate weather info, as well as the local knowledge to apply this, give you the runway condition and any other useful info (e.g. fuel pump U/S).
I regularly fly to airfields noted as "strictly PPR", some really seem to want you to phone before you go, others are happy with just the radio call.