[iLemming]

Lisp is tricky. Pretty much every programmer for whom it's not their very first PL hates it initially, but then there's a time, a threshold after which no other language feels more readable than Lisp.

Using structural editing idioms and the REPL, usually makes the process less vexing.

[zshrdlu]

I think for some people it's an aesthetic knee-jerk reaction and the fact that it's "unusual" for a programming language. It's not like their brains "can't grok" -- it's just syntax after all. People don't tend to have that reaction to xml for some reason. It's data, so it gets a pass. But then this is code-as-data and they have to break that barrier conceptually and then get past the aesthetic knee-jerk reaction.