At some point you have to also consider why most programmers are used to imperative programming.
It could be you're rationalizing from a first principle ("it must be equally easy, so if it has not caught on it's because programmers are not used to it").
> why most programmers are used to imperative programming.
Probably because that's the paradigm of the most popular languages, the first paradigm everybody learns in college and university and likely the first language a person will encounter? Because most programmers are despite what they would say about themselves in public, actually stubborn language bigots? I would think about that because it puts functional programming (or logic programming (or proof-based programming (or stack-based programming))) at a disadvantage and a fair conclusion cannot be derived from uneven exposure.
Consider the actual research done in this area, classes have demonstrated that whatever the language, there is always the same distribution. Those that excel (small group), those that succeed through hard work and do good (most of the group) and those that just don't get it and fail (small group). This has been shown to be true for C, Visual Basic, Pascal, ML, LOGO, Scheme (SICP!) and even Coq!, which is a proof-assistant. Probably Prolog, too, but I haven't looked at that. You can easily google this, just search for things like "lecture/semester findings" and "student reactions/performance" and insert your language of interest.
>Probably because that's the paradigm of the most popular languages, the first paradigm everybody learns in college and university and likely the first language a person will encounter?
That is just a rephrasing of "they are used to imperative programming". The question is why.
>Consider the actual research done in this area, classes have demonstrated that whatever the language, there is always the same distribution. Those that excel (small group), those that succeed through hard work and do good (most of the group) and those that just don't get it and fail (small group). This has been shown to be true for C, Visual Basic, Pascal, ML, LOGO, Scheme (SICP!) and even Coq!, which is a proof-assistant. Probably Prolog, too, but I haven't looked at that. You can easily google this, just search for things like "lecture/semester findings" and "student reactions/performance" and insert your language of interest.
How does that work in real life though -- when pragmatic issues get into play that are absent from "implement this algorithm in whatever language".
It could be you're rationalizing from a first principle ("it must be equally easy, so if it has not caught on it's because programmers are not used to it").