To explain their decision, the governing bodies issued a 40-page report. Section 2, titled "The Underlying Rationale for Rule 14-1b and Its Benefits to the Game," gets to the crux of the issue. Namely, what constitutes a golf stroke?
A key excerpt:
If you agree with the governing bodies' view of what constitutes a golf stroke, then you probably agree with the adoption of Rule 14-1b. If you don't agree, then you are probably an unhappy anchorer.
This traditional form of golf stroke has prevailed throughout the centuries since the game began. It is true to say that one can find isolated or episodic examples of anchored methods of stroke dating back into the early 1900s, just as one can find early examples of almost any method of stroke that creative players might invent or try, such as putting in a croquet style (seen as early as the 1900s or before). But it is only recently that a non-trivial and recurring use of anchoring methods emerged, first with the long putter in the 1980s and then with the belly putter at the turn of the 21st century—an extremely short time in the history of this 600-year old game and not reflective of any established tradition.
The concept of intentionally immobilizing one end of the golf club against the body, in a manner equivalent to creating a physical attachment point to use as a fixed fulcrum or pivot point around which the club can be swung, is a substantial departure from that traditional understanding of the golf swing. Reduced to its most basic elements, golf involves a player swinging a club at a ball to move it toward and ultimately into a hole. The player’s most basic challenge is to direct and control the movement of the entire club in making that swing.
Anchoring the club while making a stroke also involves a challenge, but it is a different one, in which the player uses the immobilization and stability of one end of the club as an essential component of the method of stroke. It is not the same as freely swinging the club.
I agree with their view.
They waited way too long, yes, which has caused a lot of problems (and perhaps more to come in the form of lawsuits, disputes and implementation issues), but I ultimately agree with their rationale and decision. The anchored stroke is not golf.
Read the full report:
EXPLANATION OF DECISION TO ADOPT RULE 14-1B OF THE RULES OF GOLF