I’ve actually noticed the same thing in reverse. Hardly any UK based bridge systems support toll free international dialing (Including a major Telco I speak with quite frequently).
Of course, unless you’re paying the bill most people don’t care. The other thing is that if you do want to set up toll free international dialing you usually have to set it up on a country by country basis. I guess if you primarily do business with just one country it wouldn’t be a big deal.
Unfortunately the standard right now is “toll free” for locals, everyone else is on their own.
-David