While I can’t disagree with learning to ride on dirt, I don’t think it needs to be a prerequisite for everyone. Certainly MSF classes and parking lot practice until you are familiar with the basic clutch/throttle mechanisms, then riding on roads that are as traffic free as your particular area would allow. However, dirt isn’t practical for all of us, even up here in Vermont I don’t know of many areas that I could easily access.
Not to downplay the power of smaller bikes but if someone isn’t able to master the throttle on a Ninja 250 with a reasonable amount of practice then maybe riding isn’t for them. Actually I can’t comment on a Ninja 250, never having ridden one, but the Suzuki GZ 250 that I took my BRC on, not saying that you couldn’t get yourself hurt on it, because you can get yourself killed on anything, but that bike is not going to take off on you unexpectedly, you really have to coax it to get it going. Again, not saying that learning on dirt is a bad idea, but to put forward that riding cannot be learned on public roads I think is doing a disservice to some.
TR, no disrespect is meant by my disagreement, I realize you probably had more time in the saddle by the time that man walked on the moon than I currently have, I just disagree with you on this point.