The main reason is that they are not able to bat against Kuldeep. that is why they got beaten in T20 series and now they lost first Odi very badly. Hope that they bounce back in 2nd odi and give some more competition to India.
Always new spin bowlers to face take some time but if the bowler doesn't have many variations then they can't survive for long in cricket world because these batsmen will learn tricks to hit those balls. Whatever the reason but India is playing good on this trip and winning overseas matches is a good thing for preparing a team for world cup. Mostly India may win this one-day series as well if England batsman can't play against spin bowling.