Generally speaking, Windows Update drivers are posted when either Microsoft or a hardware vendor finds a flaw in a previous driver that is very widespread.  For instance, if a flaw is found in a driver that originally shipped "in-box" with the OS, it is a likely candidate to be fixed with a Windows Update patch.
Microsoft uses OCA (
Online Crash Analysis) to determine which flaws are affecting the most people.  Any hardware or app vendor who has signed up (
https://winqual.microsoft.com/Default.asp) can participate by reviewing and obtaining the crash data that Microsoft collects whenever users click on "Send this information to Microsoft..."  Generally speaking, if the crash is common enough, Microsoft will proactively work with the hardware vendor and, if request, make a fix available on Windows Update. 
What I am not too familiar with, however, is how the Windows Update program determines whether you are running suitably updated drivers.  I too have seen it offer me drivers that are actually older than the ones I was running at the time.
Generally speaking, if you are savvy enough to check for driver updates directly from your device manufacturer, then you can safely ignore the driver updates at Windows Update.  But for the other 90% of the population, Windows Update remains a convenient mechanism for pushing fixes for some of these nasty crashes to computers that would otherwise continue in their original state forever.