I don't think there's a unifying reason why programming languages languish in obscurity; it's certainly not because they're "too powerful." What does "powerful" even mean? I used to care more about comparing programming languages, but I mostly don't these days. Actually used/useful languages mostly just got lucky: C was how you wrote code for Unix; Python was Perl but less funny-looking; Ruby was Rails; JavaScript is your only choice in a web browser; Lisp had its heyday in the age of symbolic AI.

Forth and (R4RS) Scheme are simple to implement, so they're fun toys. Some other languages like Haskell have interesting ideas but don't excel at solving any particular problems. Both toy and general-purpose programming languages are plentiful.