For his allegiance is in the end, towards G-d. Which one gathers, yours is not. Can understand why you'd be jealous. Richard the Lionhearted would understand the pilgrim's position, Richard went to Jerusalem to live too. Left England in a rot, too. Robin Hood and all that, eh?
The same was true of John Walker Lindh and Richard Reed, but they were still traitors. This guy might not be a terrorist or an enemy combatant, but he's still badmouthing what he should consider his homeland in a foreign paper and it doesn't speak well of him.
I have Jewish relatives who emigrated to Israel myself and I don't think badly of them for it, but so far as I know they didn't take it upon themselves when they got there to put down America. The UK may have it's problems, but on the whole it is still a good and honorable country.