Golf, to me, is not ruined in any way. You touched on a variety of topics and many of them feed off each other and perhaps impact the game at many levels.
I started playing as a kid 20+ years ago before the advent of the camera, took about a decade off, and starting playing in a competitive league about 5 years ago. During that span there was not a 'method' or teaching aid (or philosophy) that I didn't stumble across or see debated on the internet. For all of the bashing that the concepts of 'lag' and maintain a 'flat left wrist' are subjected to, I remember playing with a bunch of 'TGM' guys at various golf schools over the years...and many of them could shoot well into the 60s or 70s.
What has been shown is that other ideas (or mathematical/physical relationships) are also important and there's more than one way to skin a cat.
I am still captivated by watching the Tour players play. I still look forward to teeing it up every Tuesday (during golf season) and playing in my little league. I love working on my game and dealing with various hi and low points that come with it.
This game and all that is associated with it, will never be perfect...from teaching, to course management, to golf commentary on TV, video games, golf fitness, you name it will be (and always will be) a source of never ending debate and discovery.
Erik