What exactly are you unhappy about?
The article clearly states that there has been an ugly hack in the kernel that disables a certain functionality if the name of a process starts with X. This was done to work around some misbehaviour of the X.org X Server that was fixed a bit later, thus the hack is now obsolete unless you're running rather obsolete software.
So far, so good. I really don't see what your gripe is, what you don't understand. Slashdot *is* a tech site, so possibly there will be content that not everyone understands immediately without learning some tech background. Not everyone has time to wade through several paragraphs of layman explanations before getting to the meat of an article.
Someone else in this thread posted an explanation for atomic changes. If that is your problem and I just missed the question, sorry, that word is a standard term from computer science that gets taught to every first semester student and the definition is in any number of textbooks. Just dump "atomic operation" into a search engine of your choice and look at the first three results. In short, an atomic operation (e.g. atomic mode-setting) will update one or mode values of something without an observer being able to catch a state where one part of the values have been updated and another hasn't been updated yet.
I don't know off the top of my head why this is important in this context but in a banking context it is, e.g. when you transfer money. You decrease one account and increase another. The system needs to ensure that either both or neither of the operations are done. Also, you don't want a situation where someone can see the in-between state, as that could introduce other problems.
