This is a fairly commonly used argument which puts forward the idea that since no one can be 100% vegan, vegans are hypocrites, and attempting to be vegan is in some way pointless. This argument is actually built on a tu quoque fallacy that occurs when it is assumed that an argument is wrong if the source making the claim has acted in a way inconsistent with it. Besides this, there are some very obvious flaws with this kind of “all or nothing” thinking.
Firstly, I will not attempt to dispute the claim that it is impossible to be 100% vegan, I only object to the conclusions of this premise. We live in a world built on the exploitation of animals, we find their body parts and secretions in many unavoidable products like plastics, glues and animal fibres, not to mention the animals involved in crop farming. In cases which do not involve food allergens, companies are often not required to share information about whether certain products use animal parts in their production, making it extremely difficult to even find out. In some cases, like medication, it is simply impossible to avoid products which are the result of animal exploitation. It is clear then, that unless we are prepared to live off the grid and not be consumers at all, we cannot live completely cruelty free lifestyles.
However, it does not follow that simply because we cannot do everything, we should not try to do anything. This kind of thinking for any other social justice issue would be rightly dismissed as an avoidance technique. It is impossible to avoid the products of human exploitation too, but does not mean that people should not try their absolute best to support more ethical companies and boycott those who abuse workers and exploit the third world. Similarly, environmentalists cannot ever completely erase their carbon footprint, but it is still essential that all of us try to reduce our environmental impact as much as we can, and doing so makes a real, measurable difference. While vegans still contribute towards exploitative systems, by boycotting all animal products we directly reduce the demand for those products. That matters; both in terms of not funding industries we consider to be abhorrent and in terms of being consistent with our personal morality.
This argument is based on the premise that we do not have a choice whether or not we are involved in at least some animal exploitation, but that fact alone is enough to dismiss the conclusions of this argument. In cases where there is no choice, there can be no ethical judgement. Judgements can only be made when the moral agent in question chose an action where they could have chosen otherwise, which the argument itself states that we cannot. In addition to this, the intent of an action matters. When a person actively chooses to purchase products that are the result of animal exploitation where there are other options, it is vastly different from when a person has no choice but to purchase said product due to a lack of other choices, despite their intention not to take part in animal exploitation.
The kind of simplistic ethical binary involved in this kind of argument only makes sense when it is perfectly possible to avoid any complicity in an unethical act, but this is simply not the case when it comes to animal exploitation. What this argument essentially does is blame vegans for the actions of the industries which they are dedicated to opposing. Those putting forward this argument are merely pointing to those making an effort to reduce the harm they cause and trying to undermine their efforts by stating: “Look- you are doing it too!” This is no more than a blatant ad hominem attack in an attempt to avoid critically analysing their own behaviour. Dismissing the efforts of someone trying to do something just because they cannot do everything is both cynical and utterly irrational.