For someone who doesn't have enough hours in the day to receive "proper Scheme training" and already (sort of) knows Clojure could you go into detail about what you mean when you talk about it being "messed up due to kitchen sink syndrome."?
The examples of well-chosen set of basics is Scheme R4RS, or pg's Arc. The examples of so-called natural selection are CL (an attempt to put together the best ideas and syntactic sugar from various implementations) and, surprise! Haskell, which is a product of a merge of efforts of ML/Lazy languages world.
On the other hand, there are languages created by one individual, according their own preferences, such as Perl, Ruby and Clojure.
Ruby, for example, it is a mix of features from Perl and Smalltalk, its author liked, but, of course, the resulting language is neither a dialect of Perl or Smalltalk. It is a language of its own.
Similarly, Clojure is a mix of features from various languages, notable Common Lisp, Smalltalk, ML, plus various Python-like comprehensions for vectors or hashmaps.
There are many other clever tricks, like simplified pattern matching, at the cost of sacrificing uniformity and announcing vectors as parameter lists for binding constructs, apparently from ML, and multi-method function declarations, also from ML.
The result is a language of its own, and cannot be called a Lisp, the same way Ruby cannot be called Smalltalk. The design decisions, while mostly clever, broke the uniformity and clarity of classic Lisps.
So, in my opinion, Clojure is closer to Ruby in its ideology, than to Lisp.
> After proper Scheme training (CS61A) Clojure looks awkward and messy but very useful, as it supposed to be due to its "productivity beats clarity/conciseness" philosophy of scripting languages, such as Ruby.
As someone with "proper Scheme training" (CS61A), I've found that Clojure is actually much more clear than Scheme in most cases. The code is less beautiful from a purely visual perspective because there is more syntax, but a lot of complexity gets removed when you add literals for sets, vectors, and maps.
E.g. (defn name [arg1 arg2] body). Lists are not the alpha and omega like they are in LISPs.
But I agree it has "every single characteristic that defines a lisp", even if it looks funny to experienced Lispers like myself.
Aesthetically I much prefer standard LISP syntax + indentation , but 100% support the use of literals for the non-list data structures. Many disagree on the syntax, and if no longer having a sea of pure parens brings more adaptation I'm willing to live with it. I got the impression the syntax changes were due to that reason vs. inspiration from ML, but I'm not at all sure about that. Still, Rich Hickey is an experienced Lisper with exquisite taste below the level of syntax, so I'm pretty sure he was aware of the implications of his syntax changes.
Don't take me wrong, making the other collections syntactically first class and unifying them under the Seq abstraction is a really good thing, in fact when I appreciated that it was the first thing that got me really excited about Clojure, especially Clojure as "the next Lisp". But personally, if just for myself, I would have kept the vectors out of the syntax and depended on indentation in smart editors.
There are several types of first class syntax in Lisp: http://amitp.blogspot.com/2007/04/lisp-vs-python-syntax.html
EDIT: "Criticise" is clearly the wrong word, since your description isn't perjorative. "Distinguish" would be better.
However, while I could make such a choice in CL, or modify Clojure, the standard including indentation for such a fundamental part of a language is controlling, and if I want to be part of the community I have to follow it.
I don't see how a definition of "Lisp" that excludes Common Lisp is useful. How do you find this definition useful? You bring it up with remarkable regularity when Clojure is mentioned, presumably you find some value in it?
Occasionally, a pragmatist like Hickey comes along and says "hey look how useful this can be". Another generation of programmers takes a look at Lisp. Where will it go this time?Can Lisp be saved from the Lispers?
OP clearly hasn't hacked on any Common Lisp written by a CLOS-maniac.
Schemers break out in hives if they couldn't implement their own language on a raspberry pi in a single drunken bender.