Is that big? I don't recall exactly, but my class must have had at least a dozen, maybe more than 15. We did divide into two groups, but I think everybody was supplied their own bike. (This was a private class where you actually got your M endorsement if you passed).
I'm not sure why this discussion got so polarized. Clearly, there's occasions where people need to be sent home. But there's no reason people shouldn't be treated with respect (unless they're disrespectful). I'm sure that happens 95%+ of the time. But just like life, some people are jerks or have bad days. Sometimes personalities just don't mix.
I still feel comfortable recommending an MSF class. I imagine some of those that rightfully fail get something out of it - including the realization that motorcycling may not be meant for them. But they should have a meaningful chance at learning.