no, it's not a requirement to have it on/off
however, I think that convincing yourself that you're a great driver is a poor excuse when you get it wrong & kill someone.
I think thats a little harsh!
If I ever choose to enjoy my car above and beyond its limits of its adhesion, then I do so with the utmost respect for other road users-ie when there is no one else around. It takes far more forethought and planning to do this than merely relying on an electronic/mechanical safety net that in most peoples heads will save them from anything. ESP does not teach you how the car handles properly, it just reigns in any hamfisted inputs that the driver is giving the car and can lead to a false sense of security.
The worst case scenario is that the driver believes the car is capable of anything when in fact he should be aware of what its real limits are.
This is easily achievable on a deserted road by slowly getting to know your own car with the esp switched off. In anycase, the latest incarnation of VAG's esp never fully switches off and will step in just as you about to have fun/kill someone.
By my own admission, I have never portrayed myself as a great driver. I love cars and I love driving. I am a very courteous, very conscious driver and especially so in this ever increasing politically correct world.
Most road deaths occur because someone is not paying attention to what they are doing. Enjoying a car whether on the track or the public road commands all my attention and I do not see it as a
problem on the road if it is safe to do so?