I really haven't heard a viable argument for why we wouldn't develop these resources. That question, IMHO, is more valid and harder to answer than why we would.
First, there are potential environmental consequences and the recent ExxonMobil decision regarding their financial liability for the Exxon Valdez event has not added to the perception of the petroleum industry being environmentally responsible. The petroleum industry, in spite of Bot's protestations suggesting otherwise, has earned the reputation for being a "do it now and worry about the consequences later" based organization. And when the consequences later are delayed in court for decades and then reduced to a mere slap on the wrist it just doesn't inspire confidence if you enjoy the natural beauty of your environment without oil pollution or if you merely live nearby.
But, pollution concerns aside, what is the point? If these environmentally sensitive areas were able to support a strategy to make the United States actually less dependent on the Middle East for oil for more than a short period of time, it might make sense. But they won't. And, they won't make the price of oil budge on the open market. Every open market barrel we don't buy will be snapped up the India or China or Europe or someone else. Which means every barrel of domestic oil will be priced according to the open market. Which means the consumer of this domestic oil in America will see nothing in the way of a price drop.
In the scheme of considering domestic oil deposits a strategically valuable commodity, there is no reason if it has no lasting or significant effect on the price of open market oil, or the continued availability of oil, why these domestic resources owned by the collective citizens of the Unites States of America should be turned over to petroleum companies to convert to cash, just because gas costs $4.50 a gallon. Other countries pay twice that and have a similar or better standard of living. High energy prices has brought about conservation means instead of a steely eyed focus only on enabling more consumption. And their approach works now, and will work even better when there is actually less oil to go around.
So, the reason you see no point to debate here isn't because there isn't one. It is because the real debate has been stifled while the usual "libs" vs. "neocons" argument has diverted everyone's attention from the real issue. There is a dwindling supply of oil, we import the large majority of the oil we now consume from other oil-rich, for the moment, countries like most of Europe and India and China. Energy fuels our economic engine, it is the technical development in our lifetimes most responsible for our present day way of life. Yet we have no energy policy, as a nation, to secure our future. Instead we get wrapped up in petty partisan political bickering while the opportunity to head of the looming crisis with the least disruption, and possible growth opportunity that will overshadow the 1960's Space Race, to our economic engine and our way of life.
Yeah, let's ignore the strategic importance of using Middle East oil first and buy the fabricated just for us story about how offshore oil will lower prices and ensure we become less dependent on Middle East oil. Again.