Why is it so hard to obtain dual citizenship in the US and the UK?

The harder it is for people to become citizens, the more illegal immigrants there are. That, added to the fact that these immigrants have huge incentive to move here, mean that often people are willing to do it illegally. The more criminals, the more government spends on coping with crime which also means they have to tax more. This subtly makes the government more powerful, and is all part of the New World Order. Either that or we're really conservative and hate them 'cans.