Keep in mind that writing something like this is not actually going to be perceived as helpful to most people who may have difficulty with Haskell. Consider a couple of possibilities.

First, you may be unusually quick, gifted, clever -- whatever you might want to call it. In this case, the new concepts in functional programming might come easy for you. That's great, but to people for whom they don't come so easily, this could easily be considered discouraging, or else bragging.

Second, consider that maybe you haven't advanced as far in learning Haskell as you think you have. In my estimation Haskell can take you up an abstraction ramp, that has no clear and obvious "end." As a research language, higher up that curve is some really mind-blowing stuff. So unless you're SPJ or beyond, I wouldn't be quick to claim that Haskell isn't "unusually hard to learn."

Third, you may be a stage in your life where you can put a lot of free time into learning, but recognize that not everyone is there. In my twenties, I worked much more than full time, and in my spare time worked on yet more programming, teaching myself other languages and environments. Really in retrospect it's fortunate I didn't damage my physical or mental health more than I did. But not everyone is in that boat now. In particular people who are older and have "work/life balance," who are professionals in some form of software development, may find that their employment doesn't offer them much in the way of opportunities to learn another language, and the life part of that work/life balance doesn't allow much time to do so.

Me, I'm somewhere partway up that ramp and proud of how far I've come (I feel like I can use at least simple monads now) but still very aware that there is a lot I don't fully grok (currently trying to get my mind around arrows). And I agree, I completely recommend it, but just maybe don't be so glib to claim it is not hard.