The main reason why oil is being extracted from sands is the current price of oil. Unless something has changed, the cost of extracting 1 barell of oil from the sands in Canada is between 25 and 30USD. 12 years ago that was the cost of 1 barell of oil, pretty sure it's now well over a 100, haven't checked in a long time. So it's very profitable to dig up the sands.
I get slightly pissed off at all this eco talk. We pay for oil in every item we purchase - be it bread, electronic equipment or furniture. All the goods have to be transported and most transport involves the use of oil in one way or another. So unless you grow your own food and live in a bush, you have no right to complain about companies extracting oil at a high cost to the ecosystem. Essentially, you're generating demand for oil with almost every purchase you make.