They don't drive purchases; they drive adaption. A user is less likely to bother downloading a framework if the app they want it for doesn't look that great. Th

They don't drive purchases; they drive adaption. A user is less likely to bother downloading a framework if the app they want it for doesn't look that great. They may decide it's not worth it, and not install it. If someone makes a truly "killer app" for one of these competing technologies, it would theoretically lead more people to install whatever framework it was on.