Veganism is about causing the least amount of harm, not being perfect about it each and every single time. We vegans already know that veganism isn't perfect and that animals are harmed in the process of protecting crops, harvesting them, and what not. But that's never what veganism called for did it? The definition itself says that you should avoid causing harm wherever possible, not that you should roll up your sleeves and try to radically change society right this very instant.