There are A LOT of different programming/automation paradigms in the world, lots of different languages, declarative, functional, OOP, imperative, logic, etc etc, maybe some of these students just can't get the convoluted mutable and unsafe structure of a Python or Java program but they might grok and appreciate the safety and simplicity of ML/Haskell or the flexibility of Lisp, why would you turn them down in such a way or force them through a path they don't really need to go through?
During my first year of Bachelor Computer Science at University we had introduction to programming in Scheme. It was a mind-expanding experience to me, I already knew how to program in C, Java, C++ and C# with a bit of PHP/Javascript back then and I was much ahead most of my peers but still I sat at the computer, trying to earn this alien language to me, and luckily I was humble enough to force myself through it and adapt my mind to a different paradigm. I know for certain that a lot of my friends and colleagues who already knew how to program struggled hard on that exam and some had to re-take it the following year (Which was unfortunately changed to C++ and they managed to pass without troubles) simply because they didn't think Scheme was a "real" programming language or useful at all. It was just too different from their previous experience.
What's even more interesting, I know some people from that class who had never touched a programming language before and weren't particularly strong at math. Those people are the ones I recall enjoying the course the most, they found it the easiest among all the other courses we had and passed it with excellent grades. Simply because their mind was apparently better wired for such paradigm and they had no preconceptions or prejudices that prevented them from learning it properly.
So my bottom line is, what makes you think that some people might not just have a "differently wired" brain that makes them think more easily with a different non-imperative paradigm for programming?