I don't like the idea of wasting oil. I am confident that there will be alternatives available in the not-too-distant future (hopefully in my lifetime). Actually, I believe the technology is already there, it just needs to be rolled out. BTW - I will be the first one to install solar panels on my home when I have the chance.
The bottom line is I am concerned for the safety of my wife and (future) kids. Certainly, a larger vehicle does not guarantee their total safety, but at lest they'd have a better chance of survival should something happen than if they were in a little sub-compact.
Development must continue until the alternatives are more efficient and therefore cheap enough to compete in the market with current production. If the cost makes the alternative more expensive then it is not ready to be rolled out. Electric cars are an example. Costs are calculated for capacity, reliability and safety as well as for mpg.