Because American market is not European market.
UK market is much closer to European market than America is (it is in fact part of the European market and legistlation).
Yes, there are differences within EU member countries, but America is not in that scope. If you believe it is, you're delusional.
The EU market needs to align. There can't be EU and UK prices, that's shit.
And yes, it would have been great if they'd gone the other way and lowered the EU sub to UK level. But they didn't - I'm happy we're going to have somewhat normalized European prizes at least.