Yes, I believe it is folly to try to build a "general purpose" language these days. It's just too much work to clear the bar for adoption (i.e. what do you offer that C/C++/Java/C#/Python/Ruby/JS don't). A language could be great in many ways, but as you say, you have to be able to solve problems you can't solve otherwise with it.

It seems like most newer languages that see some adoption have a solid niche, like Erlang/Elixir, Julia, or Elm.

A friendly reminder I posted over on reddit :)

http://colinm.org/language_checklist.html