Well for starters it's inconsistent with the meaning of the characters used, I often switch between languages where => is a valid construct meaning the same thing as <=, switching between JS and PHP it gets even more annoying...
...and (e) => ( e + b ) is one step removed from brainf*** as language syntax goes.
But then I think C syntax in general is painfully and aggravatingly cryptic. I wouldn't even use C based languages if there was actually a choice... but then I'm a Wirth language guy. Having spent a good chunk of the '90's working in Ada, I generally think C syntax is part of why most software is buggy wrecks, They underlying language syntax itself is DESIGNED to make programming as L33t as possible. Likely to convince "normal people" that programming is difficult.
To be fair, I'm not convinced that this is a joke:
https://www.gnu.org/fun/jokes/unix-hoax.html
In the majority of usage cases for arrow functions, it seems to fall into one of three categories:
1) Stuff that shouldn't even involve functions
2) Stuff that could be done with a normal function cleaner/clearer
3) Wah wah, eye dunz wunna type teh wurds!!!
That last one being typical of the twitter generation TLDR "Aaah wall of text" nose breathers.
You know nose breathers, right? The halfwits who will wear the mask but only of they can pull it down past their nose?