I've recently seen a poorly accessible #WindowsForms app. Disclaimer: WindowsForms, although it's old, is my favorite way of developing Windows apps. It's sweet to write in (for most part), it's reasonably fast, and it's accessible out of the box because it uses native or near-native controls.
What did I learn? If you want your app to be inaccessible or you have really bad development habits, no framework will help you.