Yes, but suppose you could write the same program in two languages, a classic imperative one, and a purist and difficult FP language.
For the sake of argument, let's assume the classic imperative language is easier to approach for rookies. If it's also the easiest language to write bugs and make mistakes with, wouldn't the "harder" FP language still be a net win? As long as its learning curve isn't unapproachably steep -- i.e. so steep that your time to market becomes awful -- what is the advantage of the imperative language's ease to hit the ground running and writing lots of bugs?
If language 'a' lets a person write a program with 'b' bugs in time 't', and language 'aa' lets the same person write the same program with 'b' bugs in time 't-n' then there is a clear net win for all 'n' > zero.
If 'aa' also has the advantage of providing semantics for producing significantly less buggy code in time 't-n-m' at some future time then that is also an advantage but a distinctly different one and one which can be deferred [and probably will be given a significant learning curve].
The first step toward the modern automobile was the 'horseless carriage' not the Countach.
It's greatly overstating the learning curve. It's possible to pick up Haskell by simply writing a few small applications tackling different parts of the language in each one. This can be done in a few months. Not to mention there are now numerous resources available for free such as learn you a haskell, real world haskell, and countless blog posts.
> The first step toward the modern automobile was the 'horseless carriage' not the Countach.
Lamborghini makes shit cars. The only reason people rave about them is because they have giant engines. A car without a reverse gear is one of the stupidest ideas in automobile history.
I used "Countach" for its word value. It's alliterative and has little rhyming potential and is loaded suggestively with images of suits with shoulder pads. An absurdity is not accidental.
That is because it "makes it easier to program imperatively" more than any other language I've met.