It is plain that Joe Public does care about the price of fuel but at the moment he probably blames Bush and Blair for stirring up the ME and causing the current price inflation. Whilst this may be justified even Joe Public understands that a secure oil supply needs stability in the ME and the forces to ensure that.
Pulling out of Iraq now would only serve to encourage those who are currently involved in the anti-western terrorist action. Joe might not understand that but then he probably reads a tabloid newspaper and votes Blair.