The post we are commenting on was by a person who was not making a claim, but relaying an experience. I will paraphrase three arguments: the parent post blog link was saying "look, I'm not an amazing programmer, but in my experience, armed with Common Lisp, I can approximate what I see ur-programmers do with other languages at Google." He in turn was replying to a person saying "I don't think Lisp makes you more productive." The "Lisp is not really a super language, it has nothing to show for itself, and I could make similar claims about logo." thing got interjected by you, I think.
"Moreover, in no field of creative human endeavor have popularity and worthiness been correlated. You think all those billboard top 10 acts came from Juliard?"
"Are you arguing that for music that college serves little purpose? That we're entering some type of music education bubble. :-)"
No, I think that's what you're arguing. I'm saying Lisp is worthy, and should not be judged by its popularity, because the worthiness is what reallly matters. You're arguing it has "nothing to show for itself". I'm sure with a Sun Java marketing budget and the right people we could make Lisp as popular as we wanted. We could have whitepapers and case studies to "show" as much as you like. I'm only concerned with popularity when people dismiss my arguments about worthiness the minute they assess the popularity. I have the same problem when I try to tell them about Sun Ra or the Residents.
So all that being said, to address your actual point (however disjoint from the OP it might be), nobody's claiming it's a "super language", just often better for the people who commit to using it despite it's unpopularity. I can back up my claims of betterness with arguments about worthiness, but not about popularity, but then I don't think the later kind of argument matters in the first place.