I am rather curious as to why there are seemingly arbitrary restrictions on the ends of platforms. Some platforms also have the "passengers must not cross this line/point" signs a good few metres from the end of the platform as well. There's some cases where the reason is rather obvious (e.g. disused length of platform, bad condition, signalling equipment) but there's seemingly nothing in this case?
Even where signs are provided, some stations still aren't happy with you going to the ends of platforms (even when there are trains that stop that far down). I've been confronted by swarms of concerned staff members at two stations - once when walking up and down the platform on a cold day waiting for a train, and once whilst waiting for a train, fully adhering to and quite a distance from the "passengers must not pass this point" signs.