Although these alternate syntaxes may be helpful to newcomers, they have never caught on. Expert users actually prefer the parenthesized form; so anyone working in Lisp for very long has to learn to deal with it -- and usually, once they do, they find it preferable.

You said it yourself: programmers preferred S-expressions, so they became the default.

The other important point here is that the non-Lispers are right, in a sense: editing Lisp without a paren-counting editor is just as tedious as one would expect. But with a paren-counting editor -- and even better, with something like Paredit that keeps the parens balanced at all times -- editing actually becomes easier, more fluid, and more pleasant than in other languages.

That is why expert Lisp users prefer the parens.