it boils down to 2 options
1) Blizzard force projected textures. Game is now unplayable regardless of if you are a casual who doesn't do M+/Raid
2) Blizzard don't force projected textures. People who want to M+/Raid need to turn them on to do so or upgrade. People who don't do M+/Raid are not impacted.
Some people will agree with 1), some with 2). All this thread has been is people arguing one way or the other and there is no obvious answer.
/thread.