This is a hilarious argument from the US carriers and their Euro partners. They are clearly running scared.
Two questions to consider showing examples of connecting-traffic hypocracy:
1. What proportion of KLM passengers are actual O&D passengers to/from AMS? Not a lot as quite a few are connecting to places outside of the Netherlands.
2. Do the big 3 US carriers turn down connecting traffic in Atlanta/Chicago/Dallas for passengers flying between Asia and Latin America? No.