The claim here is that:
The real reason that vegans tend to oppose meatless Mondays is that it gives the person a feeling of warm absolution by contributing literally nothing. I mean, if you think about Meatless Mondays, the idea is to go from 100% meat eating to 87%, not even taking into account that trading in a beef burrito for one loaded with cheese and sour cream still contributes to animal deaths and fuels the calf-slaughtering business. Flexitarian in this way is a worthless term.
It's not that weird to see little difference between raping and "only raping a little". Or "abstaining from murder on Mondays". Typically, people discuss other criminal behavior in absolutist terms. Why is it weird to consider "I put baby chicks in a shredder" not a real step up from "I cut an animal's throat"?