Windows updates are extensively tested before release. But inevitably there will be some problems. All non-trivial software has bugs. This has always been true and I can't see it ever changing.
Considering the millions of computers running Windows it would be shocking indeed if no one reported some problem following an update. However extensive the testing it is impossible to test all combinations of hardware and software. And also understand that many of the reported problems have nothing to do with the updates at all. Many of the problems are due to failing hardware, overclocking, or buggy drivers
It is in the nature of things that individuals who experience problems with updates will make it known, sometimes very vocally. Hardly anybody will start a forum thread saying that an update took place and everything went well. This isn't news, nobody is interested, nobody cares.
In all the years I have been using Windows I don't think there I have ever experienced a problem with a Windows update. Unfortunately, that is not true of application updates. I pay little attention to forums and blogs reporting some problem with the latest update. This is to be expected.