Ok, I agree with you. I own a copy of Mathematica myself. This topic just very much interests me, because there is this dilemma with this kind of software (I am working on something like that myself): It is so much work, you need to charge for it; on the other hand, for widespread adoption it probably needs to be open-source. What do you do?

I know. I just picked on it because on one hand it is great that Wolfram was able to execute on his vision and make it work as a viable product. It needs a lot of resources to make something as great as Mathematica. On the other hand, an essential tool like that, you want to own it for life and grow with it, and I don't think that is quite possible with a "product".