In response to the OP, the simple answer is that the London airports (well, one in particular), for obvious reasons, tend to have better funding than elsewhere. In other countries airports are publically-funded and subsidised. In the UK airports are left to it themselves in a market where airlines demand lower and lower charges yet expect higher efficiency/better equipment, and the travelling public have become used to the fatally flawed, nay destructive business model of ever-lower-cost-fares-at-any-cost.
Things like DATIS cost money. ANSPs don't have it so it's passed on to the airport. Who have no money, so its passed on to the airlines... who won't pay it, so that's passed on to passengers... who won't pay the higher price. So things don't get done...