what reason do the UK have for doing this?
How much do you think the UK Government rake in every year from the likes of Hills, Corals, Ladbrokes, Bet365, Paddy Power etc?
And how much will they rake in from bitcoin sportbooks present and future?
I think that may answer your question.
Yep! It's purely so they can get their hands on their cut. No doubt they would provide a different answer if you were to ask them though.