Clojure and certain Scheme implementations prove that X and Y are compatible, but most CLs have atrocious package management when compared with Python, Ruby or even Java. Lisp's extreme flexibility doesn't remedy that at all.
Why would it? I'm not sure I understand the argument.
And also, just for an example: In my experience, Clojure's package management beats Rubygems for purposes of a project. You specify your dependencies and their versions (including the Clojure language itself) and a script updates them from the whatever repos you specify. It's taken the Ruby ecosystem some time to come up with RVM and Bundler which accomplish the same things. These kinds of things (package management) are available for Lisp languages today.
Of course CL only recently got http://www.quicklisp.org/ which seems to make some strides in this area.
Try omitting parenthesis around your Lisp expression. Or try forgetting to balance your parenthesis.
Common Lisp has #: and : and :: and ` vs ' and #+ and #. and a whole slew of others.
The point is, lisps have sometimes been referred to as "syntaxless" historically, for the reason that the grammar is that of the AST, not an arbitrarily designed grammar.
Ie. machine's grammar vs language designer's grammar.
You are right in saying it is not entirely correct to refer to them as syntaxless from a purely technical, linguistic point of view. But by throwing out his point as "technically incorrect", you are missing an important point about lisps.
Also, mentioning tokens that are used in Common Lisp doesn't quite compare to the verbose, heavily syntactical grammar of say, C++. Let me know the next time your lisp implementation throws you something called a "syntax error". You can't even get code to compile when you miss a parenthesis, which takes about three seconds to locate, tops.
This is bullshit. Python can also modify it's own code at runtime and yet it's one of the most package-complete languages. But it has a single defining implementation, so if you write your package, then every Python user will be able to use it.
Have a look at Clojure and the rate it's gaining new libraries. Lisp features don't seem to hinder that. A single implementation (and what follows - non-fragmented community) helps it greatly.