[vkou]

Maturity comes from:

* Millions of person-hours being poured into a language...

* ...Over a long enough time period that the language can go through several develop-eval-improve cycles - that take real world use cases (And not one-liner bubble sort implementations) into account.

In this sense, it doesn't matter whether or not Haskell was invented in 1890, or 1990. #2 is required for maturity, but so is #1.

(I am not a huge Python fan.)

[seagreen]

Absolutely. In fact, one of big things holding back Haskell has been the immaturity of its libraries (because for a long time they were built by hobbyist and academics, with little industry support, in a language where lots of things were new and old architectures didn't work well). Happily that's now mostly behind us: https://github.com/Gabriel439/post-rfc/blob/master/sotu.md (editor support being the main exception)

[chongli]

You can't get 9 women together and produce a baby in 1 month. A lot of developments within a programming language ecosystem originate from new ideas discovered outside of it. It doesn't matter how many people you have working on a project if the crucial piece of tech they need hasn't been discovered yet.

[vkou]

No, but you also can't study 1 woman having 9 babies, and conclude yourself an expert on pregnancy. I'll prefer to get my advice from the doctor who studied 9 women, having one baby each. Note what I said about a mature language having to go through several write-eval-improve cycles.

Diversity matters. A language that one person tinkered on for thirty years is far less likely to be useful, then one that ten people tinkered on for three years. Or, in the case of Python vs Haskell, a hundred people who tinkered on it for twenty-five years.

[ska]

It is important to note that person-hours are not remotely fungible, and some contributions are even negative in the sense of "developing ecosystem maturity".