LOL, if it truly was to reduce congestion this would be a free to low cost service. Of course there is a cost of running the service but it could be subsidized by hotels (which no longer have to operate their own shuttles) as well as HAH, since this is a public and environmental service to to reduce congestion, be friendlier to the environment with less idling of dirty shuttle buses etc. However the reality is that the cost is 9GBP (which keeps rising) and is operated by a publicly traded for profit entity that expects to generate approx. GBP 200k profit from the service. There are plenty of other busy airports around the world that have lots of hotels close by that don't see the need to have a pay for hotel shuttle service to reduce congestion.