The Wikipedia article about Penstemon notes: “Although penstemons are among the most attractive native flowers of North America, Europe has traditionally been far more active in their hybridization with hundreds of hybrids developed since the early 19th century."
Why is this so? Is it that the North American natives don’t grow well in the moister climate of Europe, so the Europeans have created hybrids that do better in their wet climate? Or do the Europeans just appreciate beauty? Or...?
Good speculations, but I really don't know. But add to that the fact that the genus is completely exotic for Europeans, and that poses some extra charm.
FYI, read Wikipedia with a skeptical eye. They do a much better job now in vetting the accuracy than what used to be, but it's far from an encylopedia. Wikipedia is usually my last choice to learn with.
Here is a challenge: look somethings up in wikipedia that you already know a lot about. Read it with a critical eye, and when you find something that doesn't seem quite right, look up the reference given (if there is one!). I will lay odds that the original reference did NOT say what the wikipedia author claimed.
So was that wikipedia author purposely untruthful? I doubt it. Just careless in writing. Technical writing (which wikipedia should be) is learned skill.