That is I think one of the fairer criticisms of Haskell. I don't personally mind, but I respect others that do so.
That said, I wouldn't want 10M more users right now. The Haskell ecosystem right now has tons of breaking changes, and I think that is important. More users would freeze things in place until we have the tooling to both have breaking changes and tool-assisted migrations. Only then would I want rapid growth in popularity.
(Compare Rust's "backwards compat is really important", ....as if they they could get everything right the first time ....as if that won't lead the way of C++. Thank god they relented a bit with "editions".)