At the start of my accountancy career I worked in tax for over 2 years and I'd see it all the time, people just wouldn't have a clue about their own situation. In those days most of my companies clients came through referrals from a company who had promised to reduce the tax bill of contractors by effectively making them self employed, the problem was they had just heard the bottom line figure they had been promised by a sales person and not taken in what they had signed up to.
These people weren't exactly the same as Jimmy, they were taking advantage of government incentives for the self employed (or were supposed to) to save a little bit on their tax bill as opposed to just paying 1%, so I doubt he was as naive as some of the people that I came across. At the same time his situation is apparently legal, so I defy anyone reading this to say that they intentionally pay more tax than they legally have to.
I personally don't blame Jimmy, or any of the other celebrities/people who have been operating in this way, from taking advantage of the "loophole", I blame the people who allow this sort of arrangement to be in place to begin with. You can't just blame the Tories for this, even if many of them have benefited (I believe George Osborne is due to pay a lot less in inheritance tax in the future because of his trust fund's 15% stake in Osborne & Little), you have to also blame Labour, who in 13 years didn't close down all of these schemes, and the Tories that came before them, and Labour before that... People will always find a way to minimise tax, it's the Government's job to make sure that everyone pays their fair share and to not allow these schemes to exist.