I can’t say I left the .NET Framework altogether as our main app was developed with .NET and we still maintain it on daily basis. Whenever applicable however, all the recent stuff is being done outside the walled garden.
The following Jonathan Oliver totally resonates with my experience.
The .NET Framework was good. Really good. Until it wasn’t. Why did I leave .NET? In short, it constrained our ability to choose (which is a huge deal for me) and turned our focus inward toward the perceived safety of the nest instead of the helping us experiencing all of the possibilities out there in the big, wide world.