And your definition of what makes a Lisp is pretty strange. For one thing, Racket and Scheme are definitely in the lisp family.
See for example Pitman, Lambda the ultimate political party
http://www.nhplace.com/kent/PS/Lambda.html
Published in Lisp Pointers (a regular Lisp magazine, published in the 80s/90s) in 1994.
> Lisp users are accustomed to being able to write programs that take program texts in different dialects (or older versions of the same dialect) and process them to bring them up to date. No single common linguistic feature supports this. And yet, Lisp users are accustomed to expecting that there will be some way to accommodate the needs of compatibility and translation.
That's is what makes Lisp, in my opinion. Sharing of code, implementations, libraries, books, tools, ...
A language spectrum serves a diverse community. It is not a dead body of abstract and vague principles. It grows out of sharing and communication.
Kent knows the Lisp and Scheme landscape very well. He worked as developer, in standardisation efforts (both Lisp and Scheme), as an implementor, editor, author, etc.
A language spectrum does indeed serve as a diverse commiunity. One us Schemers are a part of.
I know my history, I just disagree with you.
> Many of the same people were involved in the standardization effort, and the creation of both.
I doubt that this is the case for R7RS.
> The thing is, the Scheme community may not be able to share code directly, but we are able to, and often do, share ideas.
That's my point. There are few ideas shared and no code. Today the various spinoffs of Lisp have their own communities. I don't say that it is bad or good, it's just the way it is. That's not only the fate of a programming language family, it also happens in other areas, that domains are divided into groups which have problems to understand each other and which are not able to track or use the work of other groups. The groups have different preferences and their topic gets an independent life.
As for r7rs, Sussman, at the very least, was on the commitee. Several other Lispers as well, IIRC, but it would take too long to check.
All the Lisps have different communities. That's why the languages are different. There's some overlap, but if the communities were identical than all the languages would be the same.
But then, you could say the same of C, C++, and Java, which don't all share code, but are all in the same family.
Steele was on the commitee for many years, although not this one.
I'd give you a list of CLers on the commitee, but I honestly can't dig through 12 people's online profiles just to prove a point right now.
Now complaints about calling Racket Scheme, OTOH, I get. Scheme has a specification which Racket doesn't comply to: they changed the name for a reason when they started to deviate. Calling Racket Scheme is like seeing a language that's kind of similar to C and just calling it C.
Sorry, I don't have that argument.