Americans: I certainly don't think Americans are too insular to deserve a world-literature prize. Many poets think John Ashbery would deserve the Nobel, and given his influence on poetry in other languages (French and German being the two that I know about), that would be justifiable. Then we always hear of Roth and DeLillo and Pynchon as candidates, and all of them would be worthy. If Engdahl explicitly said that Pynchon is too insular, then he gets an F in Pynchon class; I may not be a Pynchon fanatic, but his work is global in its reach and its ambition.
As for Le Clézio, that is a nice surprise (even though he was listed at 14-1 on the odds list that Jonathan Mayhew posted on his blog)! I've never read his work but he is a major figure in France.
Well, the Academy seems to agree with Engdahl: since the last American won the Prize (Morrison in 1993), only three prizes have gone to non-Europeans (Oe, Xingjian, and Coetzee), unless you say that Pamuk is not European.
Morrison, though, was the last of an eight-year run in which only Cela was European (unless you count Brodsky as European).
Engdahl could also say that poets are not doing good work, at least as far as the Academy is concerned: the last writer who won it for poetry was Szymborska in 1996. BUT before that there was a small semi-cluster of poets: Heaney, Walcott, Paz, and, if we go back a bit further, Seifert in 1983 and Milosz and Elytis a few years earlier.
I just spent more time thinking about that than I should have! :-)