No, but the analogy doesn't follow; the latter can objectively be said to be inferior to modern medicine as we have science to back it up, but there is no way to objectively gauge musical quality, and as such in a discussion about what constitutes "musicianship" all cultural differentiations need to be taken into account. I wasn't actually making a point about world music, it was merely figurative, as the same argument still applies within the Western world: more music is made that is not notated than is (and regardless of whether you enjoy it, it is still music), so how can the ability with which one reads notation constitute an effective measurement of musicianship? it'd be like measuring how good someone was at their job based on the quality of their suit; it may be an indicator of their success of a businessman, but is incredibly inspecific, and disregards the fact that for many many people suits are of no use to them.
I didn't actually mention anything about "professionalism", and if you're talking about being able to being able to cope as a working classical musician then yes, of course you need to be able to read western notation. My point is that thats an incredibly narrow view on what constitutes music, given that it accounts for the tiniest tiniest proportion of all music made now, in the past, in the future, here and anywhere else.
And besides, the argument that by not being able to read music someone won't be able to understand it is a misnomer - I know plenty of people trained as classical instrumentalists that don't know their arse from their elbow when it comes to composition, and also plenty of what are being termed "musical illiterates" who consistently create what I consider to be interesting and powerful music. That it may not appeal to the majority of posters on this forum is irrelevant, the point is that the classical domain does not have ownship of the word "musician", and as such it is in no position to dictate its terms.