Maturity in the compiler != ecosystem maturity. To pick up the broader mainstream also means external tooling(ide, debugger, etc.), library code, documentation,

Maturity in the compiler != ecosystem maturity. To pick up the broader mainstream also means external tooling(ide, debugger, etc.), library code, documentation, examples and tutorials, live events like conferences and lectures, and "friends who use it" (critical mass in localized communities) When you miss some of these elements the barriers to entry go way up and the community is limited to people who can tolerate the environment without it. That's true regardless of how good or proven the base technology is. Hype and institutional use accelerates this cycle by forcing it onto developers - you end up with more people early on who say "yes, i put this into production and i can tell you how it worked."