My crackpot theory is that what stops newcomers is how unergonomic "(" and ")" are to type on typical keyboards. If mainstream lisp dialects used square brackets instead, we'd all be programming in it!
> If mainstream lisp dialects used square brackets instead, we'd all be programming in it!
You've almost convinced/nerd-sniped me to write a(nother) new lisp where we'll be using brackets for forms and lists and no parenthesis in sight. It's a wild theory.