>>The point of Python was to create a language which was simple, readable and maintainable, easy to learn for beginners, but not limiting.

Adding limits to programmer thinking and creativity is the fundamental design principles of Python.

>>It was the first mainstream language (I believe) where the design was informed by actual usability testing rather then just subjective opinions.

That's actually BASIC.

Python and BASIC come from the same Philosophy.

This is what Edsger W.Djikstra has to say about Basic:

It is practically impossible to teach good programming to students that have had a prior exposure to BASIC: as potential programmers they are mentally mutilated beyond hope of regeneration.

As someone who doesn't write a ton of CLOS-using CL, but does write CL, Shen, and professional Clojure I don't see the limitations in python very clearly. It's a language that is data oriented but not homoiconic. It has facilities for lazy stream processing built-in, as well as syntax for not only map/filter/reduce but also an object model where methods are only superficially bound to their classes (remember, self is explicitly passed and it's ETAFTP). Add in optional syntax for combined map/filter on various types (an optimization for the most common use cases for map and filter) and good repl support and you have most (but not all) practical aspects of a Lisp with a shitty prelude. There are libraries in python to fix the shitty prelude if you want to write data-oriented functions in a way that maintains DRY. Outside of not being homoiconic, python has everything. You can actually find homoiconic python in Hy.

The key idea behind SICP and the philosophy of Lisp is metalinguistic abstraction which can be described as coming up with and expressing new ideas by first creating a language that allows you to _think_ about said ideas. Think about that for a minute.

It follows then that the 'base' language [or interpreter in the classical sense] that you use to do that, should not get in your way and must be primarily focused in facilitating that process.

Python is not that language since it's very opinionated and constrained by its decisions in the design space and, additionally, has been _deliberately_ created with entirely different considerations in mind. This is very well illustrated by the idiotic Python moto "There's only one way to do it" which, in practice, isn't even the case for Python itself. A perfect example of style over substance, yet people lap it up.

You can pick and choose a few features that seem similar to Lisp features [even though they are not] but that does not make Python a good language for metalinguistic abstraction. This is a classic example of the whole of Lisp being much more than the sum of its parts, and in reality languages like Python don't even do a good job of reimplementing some of these parts. Going back to what I wrote in the beginning, what fundamentally new ideas and notions about computation that have stood the test of time did you see arising from Python?

Are you sure that first class support for programmable syntax is a very essential part of using Lisp? Any program in mainstream languages will effecfively create a domain language consisting of data structures and functions that work on said data, after all.

If you look at Norvig's Lisp-Python article and the grammar example, the code with the ad hoc language is still smaller and easier read than than the Lisp example.

It sounds like you just don't like Python? Any high level language add limits on one level but allows you to be creative on another level. Choose your poison or enjoy the creative freedom of assembler.

Djikstra was objectively wrong. Lots of great programmers of a certain generation started with BASIC. Maybe Djikstra was a smart guy, but that is a really dumb quote. In any case Python is completely different from the BASIC of the early 1970's.