When things go wrong, you might not have time to do so. When my project started to leak memory at enormous rate, I was able to find the issue quickly enough. But if I didn't know how all those things work, I would spend weeks or months learning all those things. Restarting application every 10 minutes for a week is not a good idea.

How is this different for Haskell than with anything else? If you want to be an expert in something, anything you do need to put in the work and learn it inside-out. There is no royal road. I fail to see how this is specific to Haskell...

It boils down to the steepness of the learning curves.

If I am in the business of system reliability, I will choose the language with shallower rabbit holes.

Abstraction layers are great for builders and terrible for fixers. I am both, so I need to strike a balance.

I agree with you, I don't think that it's different for Haskell.