The only thing I can think is that we are far more stringent on safety and our aircraft are maintained (maybe CAA taxed) more than the US ?
As a mechanic and inspector in the USA, I can tell you that maintenance standards here are as strict, if not far more strict and exacting as anywhere else. We are quite particular about our maintenance, and the standards behind it. That's from the legal stance. What an individual operator does, of course, may be another matter. Most operators tend to be held to, and to uphold, high standards of maintenance.