This kinda thing is never easy, and I'd really hate for somebody to tell me that I couldn't ride my bike of choice, but I have a hard time rationalizing absolute freedom of choice for inexperienced riders.
I mean, if you're all keen to let newbies ride a GP machine off the lot using the "live n' learn" argument, ask yourself ... Why not let babies play with matches? Why not let teenagers swill 151? Why not let anybody fly a helicopter?
There are limits to freedom, and we have a lot of societal norms against letting people get into more than they can reasonably be expected to handle. All the "well, I did it w/o any problems" arguments are simply anecdotes similar to the "well, I know a 16 year old girl who rode a 'busa into a crowd of pregnant social workers" stories ... anecdotes don't determine the best / right path, averages do. And if you think the average first-year rider can safely handle a 150 rwhp superbike, then you're living in a different world (or at least a different country) than I am.