> motivated by corporations' desire to maintain control over their users.
I think that's only one factor, and not a majority one.
Most users don't want to have to deal with "how it works". They want a simple, easy to use tool that works reliably... And they want to call someone to "fix it" when it "breaks". That's how it works with plumbing, cars, landline phones, stereo components, televisions, and all the electronics they've ever used.
The exceptions are computers and some smartphones, which can present cryptic error messages, have weird things in their settings, and generally make a "dumb user" feel out of their element. Think about the confusion users feel when confronted with a funny noise in their car. "I'm not a mechanic, what does that noise mean?" is no different from "I'm not a computer person, what does that error mean?" What's more, the meaning of the question is not "what, mechanically/electrically, is at fault?" It is "how much time/money will it cost to get it fixed?"
It's not just a small preference, either - the height of luxury are "push button" services that "just work". Go to a high end hotel, and your room phone has just one button. Top end consumer products of all sorts struggle to be an easy-to-use "appliance". A dumbed down user interface without developer tools is user preference, it's status, it's customer comfort and pride, all tied into one.
So 99% of companies end up designing their interfaces like that hotel phone: http://salestores.com/stores/images/images_747/IPN330091.jpg
IMO the most impressive thing about OSX is how well it supports both audiences: it feels like a push-button, high luxury, comfortable, easy device to my mother. But under the hood there are great logs and a solid BSD-based operating system model. It comes prepackaged with a lot of developer tools, hidden in a place where I would look right away, but my mother would never notice.
Sure, some companies use software to limit and control their customers (cough cough Sony), usually with sharp legal/lobbyist teeth to enforce that control. But 99% of companies out there just want to make their users feel comfortable, high status, and competent to use their device.
While I agree with RMS that this split is inevitable, I don't believe it's about control. It's about two distinct market segments: auto enthusiasts who want control over the torque settings in their high end car, and people who just want a car that fucking works. Chefs who want sector-by-sector control over their oven's heating profile, and people who just want to be able to cook a fucking roast without burning it.
