Well, Ruby isn't really homoiconic. I can't speak for OP, but to me, if a language isn't homoiconic, it can't be a Lisp.
Lisps don't have to have parenthesis-based syntax, but the grammars should be close to context-free (like Lisp's is - most of the language can be defined by two production rules). Ruby's grammar is nowhere near as simple.
Matz (except for the tongue in cheek thing about a suggested name at the end) didn't suggest that Ruby was a Lisp, just that in designing it Lisp was a starting point.
So, yes, you have every reason to doubt the claim that Ruby is Lisp -- a claim no one has made.
I don't see how that resolves your stated doubt of Matz claim that Lisp was a starting point for Ruby.
Given the benefits of Lisp that were cited in that article as defining, the conclusion is well-supported by the article.
Obviously, those aren't everyone's central concerns for a Lisp, nor are they the standard criteria for a Lisp. But, in any case, that someone said something like "Ruby is a Lisp" somewhere else in a different context doesn't change that arguing that Ruby isn't a Lisp was something of beating a strawman in this this thread.
