Second, because you are also likely to favor recruitment of other devs based on this cultural choice not on their merit, eventually creating a clique.

If I run a Java shop I want a clique of Java devs, not Golang or Rust devs.

A "multi cultural", Jack-of-all-trades kind of team, that have a broader knowledge of many tools and techniques but less in depth familiarity with any of them, is more likely to use less features from the languages and tools that they have picked for a few of their strong points only, and less likely to indulge themselves with a level of sophistication that benefits their ego (and job security) more than the project.

> If I run a Jave shop

So I know a Python shop must be a business that sells reptiles, but what does a Java shop sell?

>So I know a Python shop must be a business that sells reptiles, but what does a Java shop sell?

Coffee obviously.