Voynichese is a numeric cipher?

[Jorge_Stolfi]

Hence my claim that, if it was a plain text in any "European" language (including Russian, Finnish, Basque, Turkish, Arabic, and Hebrew) , just in a funky alphabet and orthography, it would have been cracked long ago.

But what makes you sure that this was tried systematically and completely for all european languages?  I don‘t find any tries for several languages and heavily doubt there was a systematic browse through it all.

But where did you look?  

Over the past 100+years, for any "European" language L there must have been dozens of speakers of L who saw the VMS and guessed it was L with "just a funky alphabet and orthography".  If that was the case, some of those people would have easily cracked it.  

(In fact, many became convinced that it was indeed L with a weird alphabet and spelling, and persist on that belief to this day.  Many others eventually realized that it was not the case, and gave up before posting their theories.)

In general, this argument is also flawed, since Cryptos is also written in “some kind of European” language.

But the Kryptos challenge is not "just a funky alphabet and orthography".   AFAIK, historical cipher challenges that have been hard to crack (like Copiale, Kryptos 1-3, and the Zodiac Killer letters) were definitely encrypted, in ways that made it impossible to indentify the words.

All the best, --stolfi