Metaprogramming capabilities. Most people seem to prefer keyboard macros or cut-n-paste to actually writing language-level macros.
Anyway, Lisp (and many other languages) gives you a lot of tools to make programming more thinking-intensive and less typing-intensive. Since typing is easy and thinking is hard, it follows that many people will prefer the language that makes you type.
I suspect there's a good bit of truth in your statement. I feel compelled to point out that it's incredibly short-sighted of programmers to think that way. Programmers spend a lot more time reading code than writing it, and it's hard to read code that doesn't use the right abstractions.
There's the problem of how you define readability. Many people evaluate it in a per line basis, rather than comparing pieces of code that achieve equivalent functionality. Measuring readability like this is unfair to languages that favor terseness beyond that of natural language.
In order to understand good Lisp code you need to learn new tools for expressing procedural concepts. Tools that are better, for that task, than natural language. Most people would think there is no such thing. Most people will always stick to whatever feels more intuitive at each stage of their formation as programmers. This is often a handicap to learning to think in more powerful ways.
