You are pretty much correct, but I take exception to the notion that advanced therapies are not needed for 95% of MS patients.  All MS patients can benefit from therapies that halt (and hopefully reverse) the progression of the disease, regardless of whether they have the more rare aggressive forms, or the less aggressive forms.  It is true that in its early stages of development, stem cell therapy currently carries  a lot of risk so it is likely not worth the risk for some patients, but this therapy will likely become safer over time and/or give rise to other new therapies.

And MS isn't really treatable at all.  Symptoms can be managed to some degree (like one treats symptoms of a cold virus), but the degenerative progression generally cannot be halted.

BTW, I'm very familiar with this disease.