Do we need another strongly typed language that compiles to JavaScript? If that's so important, why don't people use C/C++ and compile that to WASM for best performance too? We've got TypeScript... is it necessary to have yet another language??
Purescript is from a different family and has different goals. Overall though more languages and more choice is a good thing. Typescript (I'm thankful it's around) is just the path of least resistance and has therefore become the defacto.