Haskell also has the motto "Avoid 'success at all costs'."[1] What that means is not that they want to fail at the things they set out to do, but that they want to ensure the language is never in a position where it's so important that certain behaviors or code be kept exactly the same because there's too much code that depends on it in the wild that they can't experiment with some new interesting feature in the next release. It is fundamentally an experimental language; while it is used for certain production applications, there's a sense in which the Haskell community+language simply can not ever become a top-tier language, by the community's design. If anything like Haskell ever does get into top-tier status, it'll be something that claims Haskell as a parent, not Haskell itself.

[1]: Edited, thank you maxiepoo.

You can opt out of using those extensions in your own code, but many of them are now deeply embedded in the library ecosystem.