An interesting thing about this methodology is that it is extremely sensitive to the age of a language. It's possible to switch from an old language to a new language, but not the other way around -- so if you happen to do your measurements after a language has had some uptake but before it's been around for long enough that people have built significant projects on it and subsequently gotten sick of it, the future distribution by this method can only be 100% New Language. (Because sometimes people switch to New Language, but no one ever switches away.)
Actually, to predict the future distribution of language use, you also need to know the rate of people moving from nothing ("I just had a brilliant idea!") to each language. If everyone eventually transitions to Go, but everyone starts in Ruby, then the division of market share between Go and Ruby depends in part on how frequently people start new projects.
And of course, all things trend toward newness, so your objection there seems more about time or human psychology than the methodology of the post.
> I took the stochastic matrix sorted by the future popularity of the language (as predicted by the first eigenvector).
Emphasis in original.
I agree that the analysis makes it abundantly clear people move to older languages, but the question is what new projects are started in, and how many projects represent new versus transitioned projects.
This analysis is interesting, and gives a rough idea of what people are moving from and to when they decide to do that, but not necessarily popularity.
What the author is indexing in the end isn't really predicted overall language use, it's predicted transition target frequency.
> if you happen to do your measurements after a language has had some uptake but before it's been around for long enough that people have built significant projects on it and subsequently gotten sick of it
By this definition, it is not possible to switch from a new language to anything.
It's stated as a binary, but really this defines a continuum of newness, and the metric of the OP is very sensitive to it.