As has been mentioned earlier, it is all down to funding and with the FAA still controlling the skies in the US, this will perhaps explain why datalink clearances were rolled out en masse.
Airfields that have independent ANSPs (such as the example from Eau de Boeing) will probably only install equipment for datalink weather and clearances, should it be required by regulation. A similar analogy are (often smaller) operators that see EFBs as an unnecessary cost, with the people making such decisions viewing such technology as 'nice to have' but not essential. Furthermore, another similarity is that the ones making these decisions, will most likely not be the ones directly benefiting from it.
As an aside, the guys and girls on the FIS frequencies at London and Scottish are a excellent source for information and when the weather is bad, they will have next to nothing in the way of G/A aircraft on the frequency. Therefore they will have far more time to get information that you might need, such as the actual ATIS, RVR trends, possible EATs and the like and all of this well before top of drop for anywhere in the Midlands, as used in this example.
