Windows 8 received a lot of hate when it came out. People hated it so much that a huge fraction of windows users skipped it altogether and jumped from windows 7 straight to windows 10. What were the reasons for this hatred?

Most of the complaints people had with it were about the UI/UX changes. It introduced a lot of major UX changes with seemingly zero functional benefits.

However, microsoft didn't introduce these changes just for the fun of it. They were experimenting with windows phone at the time and wanted to unify the UX paradigms for windows phone and windows desktop. But the windows phone died a little later and they reverted back to a start menu that looks quite similar to the classic windows start menu. I have no idea why they kept the advertisements. How much does the ad revenue contribute to their net income?

So people hated windows 8 because it changed user interface drastically, and these changes were made for no reason at all from the point of view of desktop users. This leads us to the following rule:

Application developers should treat the user interface of an end user application like an Application Programming Interface. If you don't follow this rule and change the UI at your whims, you'll force the users to throw away all the muscle memory they've developed for your applications and they'll have to reprogram their habits. That is rude, and very unprofessional.

Imagine what would happen if JDK deleted a public method from a class. For example, let's say they deleted BigInteger.subtract(BigInteger val). Their reasoning being that this method is unnecessary because you can use BigInteger.add(val.negate()) and it will do the same thing. This change will undoubtedly cause a huge outcry. It might be painful enough that many users will not use java for any future projects.

Yet, we change the UI/UX of our applications willy nilly. Linux desktop environments do a complete overhaul of their user interface every couple of years.

Yes, that's right. They change the desktop user interface more that windows 8 did, and they do this every couple of years. And then they wonder why linux isn't successful on the desktop.

An Example of Good User Interface

Awesome window manager still looks and works exactly the same as it did 3 years ago. It has 8 features and 7 work flawlessly. The one that's buggy still breaks in exactly the same way it did 3 years ago.