I fail to see how using equal signs for assignment (or for defining assignment methods) is a problem with syntax, rather than an enhancement to clarity.

> unquoted regular expressions

What's wrong with that? Regexes are a different type than strings. Why should they look like strings?

> exclamation points

...again, so, what?

> absolute value bars

vertical bars used to set off block argument lists aren't absolute value bars. (Neither are vertical bars used for logical-or.)

> at signs

Again, so?

> You can't even sort-of follow what this code is doing without searching through the manual every third character.

Yes, I can, and not just "sort-of follow" it.

> Ruby syntax is worse than C++ and almost as bad as Perl.

There's no accounting for taste, I suppose.

> there are a large number of syntactical ambiguities, so writing a parser for it should be completely impossible

As Ruby does exist, and is parsed, this is clearly not the case. That said, ruby's syntax is not optimized for machine parsing, its designed to be ruby-developer-friendly rather than ruby-parser-developer-friendly.

If you want something optimized for the developer of the language's parser, look to Lisp.