Just looking at the title of his book "Japanamerica: How Japanese Pop Culture Has Invaded the U.S." gives doubts to his objectivity.
You literally just judged a book by its cover in order to accuse its author of a lack of objectivity. God I hate you guys sometimes.
No, the circumstantial evidence of the book title was placed along with the shallow exposition that made up the "analysis" and was found to point in the same way: towards a not very objective assessment by the author.
I mean, this is a the text where a teacher relates anecdotes of the japanese actively sabotaging their learning (answering "yes" even when they don't understand) in a positive context.