I took the time to read your long post. You raise a lot of good points and generally make a fair arguments. That being said, there is a central theme running through your post with which I disagree.
You argue that the point of WF and TF is to incentivize players to do that content. The actual point is to reward players who do that content. While I suspect you may think "what's the difference?", it is actually pretty significant, and key to the understanding of the design intent. The difference of course is in the causation, and it's what @
Lucetia was driving at when she spoke about the point of doing content
not being gear, but about enjoying the content. Gear is simply means to an end (so, yes, gear is important), but it's not an end in of itself. Gear results from doing content, but it should never be the motivation for doing that content.
Essentially I view this entire mess as a player problem: Players choosing to chase rewards instead of choosing to focus on the type of content they enjoy. Blizzard has created a reward structure that allows players to get rewarded regardless of the content they choose to engage in, the objective of which should be that players have the freedom to choose. Unfortunately some players miscontrue that as being forced to do everything they posssibly can until they reach BiS.
The possibility of TF items in LFR serves to prevent LFR players from feeling compelled to participate in progression raiding if they want to ever see any possibility of better gear. It is to prevent players from avoiding non-optimal content that they enjoy on the basis that it is a waste of time in terms of possible gear upgrades. It is
not to make normal/heroic/mythic raiders feel compelled to participate in LFR.
Sorry to be so blunt, but this only becomes a problem for immature players who can't regulate their compulsion to chase rewards. For the more evolved player who realises that the point of any game is to have fun, and therefore do what they enjoy, the setup is perfect. Which is why I have an issue with the complaints levelled against TF/WF. This system works well for players who get it right. But the players who get it wrong demand that the game must change in order to solve the problem. You can't fix a player problem by changing the game. All that does is screw things up for those players who had no part in creating the actual problem in the first place.