While I do agree that having a compiler accessible on a platform is a positive, I'm somewhat skeptical of the claim that anyone can learn to use it and then use it. It glosses over the enormous learning curve to develop software with the current mainstream tools (especially the ones that need compilers). If you look at e.g. Mac OS X, where the compiler can be downloaded and installed by anyone, very few do and even fewer develop software.
Our current systems are simply not designed to be extended and modified by non-experts. Even in a system like Smalltalk, where that was one of the explicit goals, it doesn't really seem to have worked out. Having the compiler and software tools accessible is only small part of the solution.
>Our current systems are simply not designed to be extended and modified by non-experts.
Yes, that is exactly the point - and it is by design, not nature.
>anyone can learn to use it and then use it
Well, this has been the case so far - or were those of us fortunate enough to have become software developers only able to attain such lofty states by chance, luck and/or good breeding? Because if that is your position: bollocks. Anyone can learn to read, and write, computer code. All it takes is the intention on the part of the learner to do so .. however when that option is denied them, because OS vendors do everything they can to profit from separated Developer tools, then it is a matter of one intention being greater than the other.
Certainly, anyone who wants to learn to write software, can. But don't kid yourself that there haven't been huge stumbling blocks put in their way in order to make the whole subject more specialized. That is a matter of economic reality at this point.
>Anyone can learn to read, and write, computer code
I agree that most motivated learners could pick up some very basic software skills, and those would be beneficial to them. In a utopian world basic programming skills would be treated the same as basic literacy and numeracy. However, at this point in time, it seems to me that most users don't care (maybe because they don't know what they're missing). As an analogy, most people could learn basic knife skills in a couple of hours and be much more productive in the kitchen with a chef's knife than they are now with the huge array of inferior point tools (cheap dull knives, garlic slicer, chopper, egg slicer, etc.). However there is obviously a big market for the latter. Similarly, I'm not sure extensible and modifiable systems have enough attraction to the average user.
Another reason for closed systems, one which I think is more important than the profit motive, is that designing extensible and modifiable systems is really hard and comes with trade-offs. E.g. Squeak (a Smalltalk dialect) allows you to inspect and modify almost everything in the system while it runs, but that also means that is really easy to screw up the system behind repair (e.g. you can switch every boolean in the running system by evaluating 'true become: false') and that supporting users of such systems becomes much harder. I am not aware of any system that has a solution to this.
Our current systems are simply not designed to be extended and modified by non-experts. Even in a system like Smalltalk, where that was one of the explicit goals, it doesn't really seem to have worked out. Having the compiler and software tools accessible is only small part of the solution.