Great post.

The subtitle of the original Mathematica book is "A System for Doing Mathematics by Computer". That was an ambitious goal back in the 1980s -- and it still is -- and there is a large part of Wolfram Language dedicated to fulfilling that vision.

However, as you point out, Mathematica's mission has evolved from that beginning. Computational thinking is one of the genuinely new ideas of our century. I am not entirely happy with the term 'computational' , since it tends to turn off the liberal arts types who could really benefit from this approach to seeing the world, but I do not have a good alternative. Keith Devlin teaches a MOOC on Mathematical thinking, and I pointed out that the course really deals with critical thinking in general, not just mathematics. He agreed, but there really is no good alternative we could think of.

I, too, am pleased with the current direction in the development of Mathematica's capabilities. There are still gaps in the documentation, annoying bugs, etc. I see progress in this area as well. For example, Wolfram Workbench has been broken for several releases of Mathematica. However, almost all the functionality that we needed in Workbench has been incorporated into Mathematica, including stack trace in version 11. The only major feature that is missing is the ability to create Documentation Center-style documentation, and I suspect that that will be coming 'soon'.

I think that the pricing model for Wolfram products is a red herring. Sure, free is nice, but you get what you pay for. The on-line iterations of Wolfram Language are free to get started, and the cost is reasonable for more functionality. The student license for the desktop version is less than the cost of a maths textbook. I have a commercial license, and maintaining it is 'cheap' compared to the benefit I get. (Granted, the initial cost in 1989 was not what it is now.) The Raspberry Pi is approaching third-world 'cheap', and you get an entire computer to boot.

The only problem I have with today's Mathematica -- and it is a happy problem -- is that it is too big to master. With early versions, I could get the feeling that I understood the language (although not the maths in all cases). Today, the program is simply to vast. The advantage that Wolfram Language has is that it is integrated (no add-on packages) and the paradigms transfer from one area to another relatively easily, so if you understand one part of Wolfram Language, it is not too hard to pick up another.