What has changed I suspect is somebody else now owns the land, somebody who isn't scared or bothered by the prospect of a public liability court case in the event of an accident - these people are in the minority these days, i'd be much more grateful than antagonised as it's a very very good place to watch / listen from especially f you haven't been there before as you can hear the engine drone gear changes etc in the valley a long time before you see the bikes. Just enjoy it while it's there .... like the rest of it