The language probably won't be perceived as "sexy" enough compared to, i.e., full-stack JavaScript. Most people don't really like SQL and aren't that good at it. Hence the continued popularity of ORMs that support the often-seen pattern of bulk-loading everything into the application server for processing instead of using a simple UPDATE statement.
We're actually first-classing a number of languages and ecosystem support precisely so that people can use their languages of choice and not just SQL or Pl/pgSQL.
Sievert could use help getting quickjs working away from PLv8