Wolf, I think there is both a pocketbook and cultural basis for the vast majority of Gibraltar. I believe not only do they see a better life in staying British, but also they identify much more with the British culture. Which in some ways is VERY different than the Spanish culture. Just look at the Faulklands. The British are VERY British there and want to remain so.
I would feel more comfortable living in Gibraltar than in Spain because I identify more with the British culture. This is due to many factors, one of which is the English language(and language is the biggest aspect of one's culture).
So basically, we must take into account both the financial and the cultural aspects of this issue.