I do wonder if creating more of a reputation for being easy in turn makes it feel easier to people.
Easy is a feeling, maybe your expectations from what you’ve read or were told play into that feeling.
I also think familiarity is a big part of being easy, you’ve already learned most of it if you’re familiar with it already.
I’ve got no idea if Greek is easy or not, but learning Spanish if you speak French is easier, since you’ve got a lot of familiarity with it already. Going from English to Spanish might be harder.
I think easy also comes from mainstream popularity, better guides, more mentors, better done YouTube videos, more examples, that all help make things easier.
And the problems about mutability don’t make it hard, people simply ignore all the bugs and still release their app to prod 
Now writing correct mutable programs, nobody’s ever figured it out.
I’ve never found Clojure hard, I’d agree with you on it being easy, or at least it’s simple, and that makes it easier for me. The issue is when someone is struggling with it, if I tell them it’s easy, they take it as a personal insult, then they’ll say, look I know C++, I know Java, I have 30 year experience with OOP, I know C#, I’ve build many enterprise systems, I know Spring, I know Python, I can figure out how to do this in Python in a breeze, etc. Basically they can take it as a judgement of their qualities, I don’t know why it’s hard for them, but when someone finds something hard, telling them it’s easy doesn’t help, maybe a minor form of gaslighting… Then again, maybe it does help in a machiavelic way 
, anger motivation, I’ll show you motivation?
But then I go back to that main point, maybe people find Python hard too, but don’t say it, because everyone knows it’s easy, can’t possibly find it hard.
I’ve also noticed that Clojure is an easy scapegoat, this took me longer because of Clojure, my startup failed because of Clojure, I couldn’t complete my story because of Clojure. Yet when you use Java, everything is broken, complicated and takes longer all the time. But nobody blames Java, then it’s a bad code base, it’s bad decisions, it’s bad design, it’s a complex use case, it’s legacy systems, it’s junior programmers who didn’t know better, etc.
Imagine a founder saying their startup failed because of Java? People would laugh, you know how many things are Java out there, you can’t use popular things as scapegoat, people won’t believe you. But Clojure is a great target for that.