The article, and idea behind the startup, seems to be that the studios are screwing over the backers and the funding corporation.

But if this is so, why do people continue to invest in these vehicles? Don't the backers of these movies, especially a blockbuster like Harry Potter, know that this accounting is going to happen?

It seems to me like there must be another explanation at work here - such as the funding corporations being set up as losers purposefully for the purposes of taxes. Otherwise, if the studios were screwing their funders so much, wouldn't they have run out of suckers by now?