The Buddha, while alive, was very strict indeed regarding the misrepresentation of his Teaching:
So, misrepresentation of the Buddha was happening while he was physically present....and 2500 years have passed since then! And the Teaching, well before KF or DI had ever set eyes on the Dhamma, had already branched into the many varied sects even within the Theravada, Mahayana, Vajrayana (etc) schools.
The suttas in the Pali Tipitaka are the closest and most reliable source of the authentic teachings of the historical Buddha (but would we want any from any 'other' Buddha?). They are probably not perfect, they might have a few corruptions (I am not qualified to judge though), but they are still the best we have. Delusion being so tricky to overcome, we surely need the aid of a Buddha, not just contemporaries who feel they have either rediscovered, redefined, or even surpassed the Teaching of One whom, by all accounts, was singularly impressive in a really huge way. He sent waves through the spiritual dimension of humanity, and the ripples can be perceived even now. I feel them whenever I read the words of the Dhammapada, for example. Such beauty, truth, and power. And the words of the Buddha (as we have them) keep my mind from straying into it's own self-serving version of truth (delusion is very tricky...).
So what I find so irritating about the redefining of the Dhamma that is going on in some circles is the presumption that ANY of us have the same singularly massive spiritual footprint of a Tathagatha. We don't. When a true One arises, we will know (not in this lifetime). Until then, I will continue to use the teachings of the most recent One as my guide.
Then the Blessed One, picking up a tiny bit of dust with the tip of his fingernail, said to the monk, "There isn't even this much form...feeling...
perception...fabrications...consciousness that is constant, lasting, eternal, not subject to change, that will stay just as it is as long as eternity."