In regards to the "nobody's vegan" idea, I'll attempt to demonstrate why it is flawed in its essence.
The "nobody's vegan" idea stems from the delusion that there is ever an absolute manifestation of anything within a universe constructed on a foundation of relativity combined with the delusion that it is those absolute's we are talking about when we identify something with a label. No absolute ideal is ever fully, 100%, completely manifest. All manifstation is a construction of degrees, of spectrum. Just as there is no absolute light, nor absolute dark, so too is there no absolute manifestation of anything within an essentially duality-based existence, and when we use the term 'light' we do not mean absolute light, but instead we mean some level of light beyond a minimum marker on the spectrum of light to dark.
If we liken veganism to light and non-veganism to dark, we can see that while there is no absolute light or dark, there is a very apparent and obvious difference between light and dark, which we can easily identify. There are also degrees of light and degrees of dark. Let those degrees, in the analogy, equal the degrees of practice of veganism or non-veganism. Then we see the uselessness in saying that because absolute light does not exist, noon-day light is no different or brighter than dawn light.
So, the very definition of "being vegan" is something that occurs within relativity - it is both an ideal and a minimum requirement, defined as anything past a certain point on the spectrum of exploitation to non- exploitation (just as we label 'light' as anything past a certain point on the spectrum of dark to light).
The minimum requirement to be vegan is to no longer directly, actively, knowingly participating in the exploitation and imposed-suffering of sentient beings. Let this=X and let Y=disregard for any exploitation of sentient beings. Between these we have a spectrum (represented by vegetarianism in terms of dietary considerations, by animal welfare in terms of being's rights, etc.). But as we see, there is no final or maximum marker or final attainment of being vegan and the definition of vegan is not to be found at that imaginary absolute.
So, being Vegan means to be living at or beyond that minimum requirement and to be ever striving to reach an ideal that is essentially unreachable, but always increasingly approachable. This idea is at the core of non-violence, veganism and AR, and, imho, at the core of a life well lived. We identify the ideals we wish to live, and then we spend our lives approaching but never fully reaching those ideals (and thus humanity as a whole can follow the same progress). Along the journey we pass definite markers (the "knots on an endless string" of eastern traditions). And this is also, imho, the greatest gift of life - infinite perfectibility.
Thus, "nobody's vegan" is based on an incorrect notion of the existence of absolutes within manifestation and/or a mistaken notion of what is meant by the marker 'vegan'. The only way the statement could be true is to say that "Nobody has reached the ideal represented by the term vegan". And that is true, as it is true for every ideal within manifestation. But many are living beyond that minimum marker - many have passed that particular knot on the string.
It is said that life is about the journey not the destination, but few really question why this is. The answer is because there is no destination. Veganism is such a journey.