Almost complete disagree on TPMs. A better comparison than a spy would probably be a consulate (ok, maybe an idealized one, located underground in a Faraday cage): Their staff doesn't get to spy on you, but if you ever do want to do business with companies in that country and need some letters notarized/certified, walking into their consulate in your capital sure beats sending trustworthy couriers around the world every single time.
To torture that analogy some more: Sure, the guest country could try to extend the consulate into a spy base if you're not careful, and some suspicion is very well warranted, but that possibility is not intrinsic to its function, only to its implementation.