One True Way
The one true way, or the mockingly misspelled wun twoo wai (or other inappropriate spelling convention) is a concept that denotes a person not only has stiff convictions and is not open minded, but also believes that their notion of the way things should be concerning BDSM is objectively better than everyone else's and that others should, and in some absurd cases, must, subscribe to their theories, methods and practices.
Because of the highly individual, personal, and intimate nature of the expression of kink many who practice BDSM find the notion and concept of being told in so many words, your kink is wrong (or that anyone's way is wrong) by those that stake claim to the "one true way", to be highly offensive. This is further doubly offensive when it is considered each person that practices kink is by some definition a deviant, and that those who have subscribed to a notion of one true way have decided that their form of kink is acceptable (or even objectively better than other ways) and that others methods should be persecuted, outcast or more generally looked down on, rather than embracing a more progressive and tolerant attitude.
The concept of one true way has been said at times to cause some to fail to want to stand and identify anything regarding BDSM for fear that it would be construed as presenting one true way and draw the associated stigma which led to an inverse problem where good information was not made available to new explorers of BDSM. See Best Practices.