Uh... of course some methods are better than others. Canning may be more convenient (read: lazy), but it's also less sanitary (which, again, is MOST important when propagating yeast), as you can't sanitize the vessel/stir-bar/foam stopper (or other contamination barrier) nearly as well as you could if you just boiled it all in the flask.
Not to mention the disadvantage of not being able to make the *exact* size of starter calculated to yield the optimal pitching rates... you're stuck with whatever volume you had previously decided on while canning.
So, it most certainly IS an inferior "way of doing it." Although simply boiling in the flask isn't even the *best* method either, since you can completely STERILIZE - and not just sanitize - the whole setup with an autoclave or adequate pressure cooker. Of course, a borosilicate E-flask (or some other appropriate vessel) would have to be used for this method as well, anyways.