Levine makes two general points:
1. There's plenty of authentic Chinese food in America, if you just know where to look.
2. Don't knock "inauthentic" (aka Chinese-American) food. It can be perfectly delicious. And after all, isn't delicious why we eat?
Actually, I think it's that second question that I find most interesting. Isn't delicious why we eat?
The answer, according to the commenters (and I think they're right) is: sometimes. Mostly, even. But sometimes we want the "authentic" experience because sometimes we eat for our brains, not just our stomachs. Eating authentically opens us up to a new world of understanding other cultures and it even helps us understand and appreciate culinary adaptations more.
It's a good discussion, thought-provoking and rational. I occasionally take issue with the authenticity nazis and with people who trade in authenticity for the wrong reasons (namely, to one-up other foodies around them). Those undesirables don't seem to make too much of a splash in this discussion, which is nice.
I'll close with Levine quoting commenter Mongoose, who sums up the way I feel pretty nicely:
Authentic ingredients are wonderful things, but when this becomes THE central focus, it's easy to lose track of what makes food deeply enjoyable, and it instead becomes a museum piece.