It's not about replacing Persian Gulf Oil. The article, is the first I have seen in the popular press that correctly stated the reason.
"There is only one world market for crude oil, and the last barrel produced sets the price for all of them."
Finally, someone in Mainstream land understands the pricing mechanism of a commodity market.
As a cartel, OPEC does not decide the price of oil. They decide how much they will pump and the market sets the price. The more oil on the market, the lower the price.
You and the author of the article are both correct, the last barrel pumped sets the price for all the rest. But since the cost of production for ANWR oil is so high, if the price of oil drops any lower it won't be worth drilling.