During my time at EGLL I don't recall ever putting the Runway state on the ATIS and only passing on state reports over R/T when reported by another pilot.
I can't speak for the times when you could inspect the runway in-between arrivals/departures but I assume now that you have to book a gap of up to 15nm in arrivals for a standard inspection it would be impossible to run efficiently if you needed to conduct an inspection every time the weather changed to update the Runway state.
I guess it's easier to ask for Pilot reports as you guys can give live up to date state reports and it would be then quicker to pass onto other aircraft over R/T.
It's a good question!
