If loads of foreign cars were driving around the UK not taxed and insured here, we as citizens may complain.
Like people have been complaining about foreign cars/drivers getting away with speeding penalties...........that's actually breaking the law, as opposed to merely operating here.
Most N reg aircraft over here are also insured here - it's tough to get a US insurance company to cover aircraft not resident in the good ole US of A. Lloyds rules.
And what about French or German registered aircraft? Does it make it OK if the letter on the side is a D or and F? We can legally own them - being all good Euro-citizens now.