Perhaps. But the scope of article is in the title. And of course there are exceptions. While it's not always wise to generalize, it does make sense to look for patterns and follow arcs. That's seems to be the author's intent.

As for C++ and C#, maybe it wasn't the money. Maybe it was the culture that attracted them? Maybe they were Danes by DNA but they identified as American? If that's the case, they it's fair to say that those languages have deep American roots.