Language popularity indices are often based on books purchased or StackOverflow questions. However educational institutions have institutionalized teaching languages such as Java, C, C++ and RDBMSs such as MySQL originally because they where free open-source, not owned by a specific company and were popular a decade ago. As a result these indices do not reflect usage of languages or technologies used professionally (as opposed to used for learning - all the students buy the books and ask questions online for the language in their course). Now that ORACLE owns Java and MySQL will this change? It doesn't seem to have yet. C# in particular I suspect is much more popular in the work place than indices show - because academic institutions had an aversion to teaching a "Microsoft" language. I am speaking in general of course - though I am yet to see even today a Computer Science student who used C# in one of their courses.

For me its not so much about design patterns or industry trends, it is about capabilities: Dynamic Layouts In Win Forms you often layed everything out with absolute positions on a "canvas". In WPF one quickly learns to use the dynamic layout capability of different panels so your app works at different resolutions, window sizes etc. and adapts. Control Customisation You can completely overhaul the look and feel of every control with a little XAML to completely fit your vision - with Win Forms you had to work the properties you had - with WPF can you replace all the parts and it still works, e.g. a ListBox can appear as a Solar System.