Yaron Minsky joined Jane Street in 2003. The success of Jane Street and the use of OCaml there is well known in finance circles. Finance is full of people who don’t exhibit herd behavior - many firms have a culture of studying fundamental causes and taking contrarian positions. That begs the question - why did OCaml not get widely adopted in finance?

Jet was purchased by Walmart in 2016. Mark Lore from Jet was appointed as CEO of Walmart to turn the company around, particular its technology operations (to compete effectively with Amazon). Jet’s tech was mostly developed in F#. Yet, Lore did not push for its adoption widely within Walmart.

IMO explaining away the failure of ML languages to gain market share over multiple decades as “herd behavior and network effects” is lazy.

Agreed. The stuff "sitting on the shelf", as your parent comment said, have problems too (eg tooling). They might solve some problems, but are far from the silver bullets we are looking for.