Ok, I won't argue with that. If you don't work with mission critical systems -- sure, #1 doesn't apply to you. Play with any language you like.
Mission-critical systems use SRE principles so no one is debugging code at 4am. If you can't solve a production issue without looking at the source code, you'veong since failed at building a mission critical-system.
Even if your app is 100% bug free and fault-tolerant, sometimes an external system feeds it invalid data and you need to figure out how to contain and revert the damage. That was my last on-call involving reading a lot of code under time pressure (thankfully, not alone and not at 4 am).
All commenters who said "It's your own fault for writing crappy code, duh!" perhaps never worked with anything sufficiently complex and expensive.
Give yourself time the next day to actually think about the problem with a clear head. At 4am trying to debug code, you're far more likely to cause more problems than fix things.
To me, I read this question the same as "Haskell's not useful when you're stuck in a well with a bomb ticking down." The language isn't the problem. It's the situation that's the problem.