I have no doubt that that’s true, that internal trade barriers are a larger issue than trade barriers between the US and EU, but they’re also kind of two different issues. The EU is not tightly politically-integrated; it has powerful member-state level political interests who are going to want to serve specific domestic interests rather than overall EU concerns. It’s not possible for the EU to wave a wand and make that go away, whereas it is very easy for the US administration to not impose restrictions vis-a-vis the EU.

EDIT: I mean, the article even mentions that, albeit not in specific terms, and only in a single sentence.

Up to now, Europe has focused on either single or national goals without counting their collective cost.

The problem is, that’s a pretty important sentence there.