Or, to restate this and amplify it a bit, Lisp syntax is hard to read because most people are unfamiliar with it. This isn't -- or should not be -- a problem if you need to learn to read a language in order to use it. (This is orthogonal to whether you want to learn it in the first place, or whether you "ought" to.) It is a problem if learning how to read and write the language isn't enough.

The point TFA raises is that people who're familiar with CoffeeScript syntax may still make mistakes resulting in completely erroneous but valid code. Yikes. And the inherent nature of whitespace or indentation makes the problem harder to detect by cursory inspection.

I have no strong opinions about CoffeeScript, myself. I just thought this was an interesting distinction, and a rare case where syntax makes a significant difference.

Mere consistency is not enough. List is hard to read because humans do not have a natural feel for how deep a set of nested brackets are, and you have to be able to spot the matching open-bracket to understand the code.

Again, it's hard to read if you are not familiar with it. Even as someone relatively new to Lisp, indentation and formatting makes a world of difference for readability.

This isn't specific to Lisp, either. I posit that if you took your average C-like and removed indentation from any reasonably sized function or method (one or more loops, one or more if/else), you would have a hard time counting brackets.

I agree that consistency is necessary but not sufficient, though, which is what I think you're getting at. Most of the time, though, consistency is clearly better than inconsistency. There's less to remember or, if you prefer, less to screw up. :)

Please note that I was not replying to TFA, I was replying to smacktoward's assertion that if you need to learn how to read a language it's not easily readable.