It pisses me off that tech companies change the user interface of stuff for no reason. If they are improving it, then great, but change just for change's sake is complete and utter bullshit. Can you imagine if car companies did this? Move the gas pedal over to the left and the brake to the right, just to mix things up a little bit?

It's because the new kid coders don't want to learn the fundamentals of the 'old-fashioned' language an 'old-fashioned' OS was written in. Imagine that all major software releases are being written by your idiot 12 year-old nephew, and that's about how it works.

Excuse me!?

Operating Systems are still written in C dialects. Lots of applications are written in them, like every iOS application (either directly or through a translation layer). Lots of people still learn them as new programmers. Lots of veterans are still using them. Or maybe you are talking about really old-fashioned like Lisp machines or mainframes?

Language is not the factor. It is a much more complex, and very human, problem.

But did you ever meet a newly hired programmer/analyst
that didn't want to start the project over again ?

Nope. Everyone wants to dream about a clean slate. Junior developers might not be familiar with the downsides of that. That's why you need senior folk around. They know about second-system syndrome and that while you can't usually pull off a reboot you can always judiciously rewrite/replace components in a well-factored system.

(Now sort of responding to Flint too and mostly just enjoying hearing the sound of my own fingers.)

In the case of Windows 8, I believe the pressure came from above to be touch-friendly and the classic desktop experience wasn't much of a consideration.

The thought might have been that if the desktop experience was poor then more people might upgrade to touch devices, thus benefitting Microsoft and their hardware partners. It might have also been a bet that they could sacrifice the happiness of an existing market to focus on where everyone says the market is going. Microsoft has the bankroll to do a lot of alienation on long-term bets.

Those are my cynical views. In reality what appears to have happened was that they emphasized touch-based over traditional interfaces. They sacrificed the desktop experience in a few places where they thought it prudent (for technical or design reasons). Such sacrifices are often guesses. They have learned that they guessed wrong and are taking steps to refine their software.

One interesting programming culture factor is that many younger developers got started on the web and are used to painlessly and effortlessly deploying refinements. That's not so much the case when you are delivering traditional software. When you are eyeballing the risks to take, I'm sure it's hard to recalibrate. "Just a UI change" costs a lot in one context and virtually nothing in the other.

"Kids don't want to learn C" is nowhere near a factor.

Also, the skill of software developers follows a normal distribution like most other skills. Most of them are pretty mediocre. Mediocre can seem "like an idiot 12-year old" to those on the right hand side of the distribution. Let me assure you that the developers building Windows (and Facebook and Twitter) are highly skilled, whatever their age. Those that can't hack it get canned.

tl;dr IME, most such mistakes are systemic at their root and not the symptom of a handful of raging morons.