It's complicated but by coincidence.... nearly every (anti British) Celtic fan I know is a YES too.
Wealth or lack of it, the next big factor. If you have any assets, a house, savings, pension, etc. why risk it ? If you are unemployed with out a penny to your name then lets roll the dice and see what happens. Things can't get any worse for that person than they already are.
Wonder how they'll get on working in England (part of the EU) while Scotland has to apply to join ? Will they need visa's of some kind ? What about Scottish people working in other EU countries ? If they're so pro- YES maybe they'll come 'home' to work and pay tax in Bonnie Scotland, like the rest of us...