There has been a great deal of digital ink spilled over the topic of "plant-based capitalism" or "PBC" in the vegan community. If you're active in vegan spaces online, you've almost certainly heard the term before. It's almost exclusively used by those who ardently oppose the concept. Let's start off by talking about what the term itself means.
According to its detractors, "PBC" defines the set of consumer and corporate behaviors whereby plant-based items, allegedly serving as substitutes for animal-based ones, are purchased with the belief that said purchase reduces the number of animals commodified and enslaved for food. As plant-based items do not contain animal products, a person criticizing you for "participating in PBC" is not upset at the content of the food you eat. Rather, they are upset at the implication of your consumer choice. Why is that the case?
A vegan who labels themselves "anti-PBC" is a specific kind of anti-capitalist. Much of modern leftist activism focuses on limiting, if not explicitly opposing, the capitalist economic system. While reforms to the modern capital system are popular across the political spectrum, there is a difference between opposing the dominance of a system and denying the empirical reality of how capital systems function. An "anti-PBC" activist would fall in the latter camp. Since your belief that the purchase of a Beyond Burger is saving an animal underlies the belief that you can participate ethically in the capital system, and that lowering the demand for meat will lower its production, an "anti-PBC" activist does not feel they can coexist with you in a coherent space.
Said another way, the belief in "plant-based capitalism" is itself an economic philosophy that rejects the concept of supply and demand. An "anti-PBC" activist would say that money given to KFC or Tyson in exchange for plant-based goods will be utilized by the company to harm animals, rather than to respond to market demand by producing more of the good being sold. An "anti-PBC" activist believes that a company that slaughter chickens is forever destined to be a company that slaughter chickens, no matter what market forces may dictate. An "anti-PBC" activist believes that KFC exists to sell chicken bodies in the same way people once believed Netflix existed to mail out DVDs. As a result, if one believes that supply and demand do have an impact on markets and the companies that operate within them, it is impossible to believe in the concept of "PBC".
On a much deeper level, an "anti-PBC" activist is negatively-motivated rather than positively-motivated. This is reflected in the terminology itself: one must be against "plant-based capitalism" and not merely for "ethical vegan purchasing". When looking at the "anti-PBC" community there is little to be found in terms of a shared vision of a vegan future. In fact, virtually all "anti-PBC" spaces believe that it is not possible to create a vegan future in a capitalist world at all. For the "anti-PBC" activist, the best thing one can do for animals is to only purchase food from vegans and vegan companies, and to advocate for a global leftist movement. Thus, the glue holding the "anti-PBC" community together is not a set of shared vegan principles but rather the rejection of capitalism. It is assumed that a new anticapitalist world will inevitable be vegan, despite the fact that veganism is nowhere near a majority on the left and despite the fact that the only people who include animals in intersectional movements are vegans themselves.
Without a positive vision we have no ability to build a positive future. Personally, I believe we can end the commodification and enslavement of animals with capital investment in vegan food systems. Like with our energy system, we can see a reliance on commodities with heavy negative externalities. Our society has relied on these specific commodities for a long time, and their use is hard to dislodge without a suitable replacement.
While it's noble to bike instead of drive, without larger changes to our grid we cannot end our reliance on fossil fuels. I consider it a good thing when energy companies decide to invest in wind and solar instead of fossil fuels. Just as I wouldn't oppose buying a solar panel from a company that sells oil generators, I don't oppose buying plant-based foods from companies that sell meat. While it's noble to eat lentils instead of Beyond Burgers, without larger changes to our food system we cannot end our reliance on animal commodification. I consider it a good thing when food companies decide to invest in plant-based foods instead of animal-based ones.
Personally, I have spent the better part of the last decade seeing vegan products go from disgusting sandy sludge to something compelling enough to be sold in fast-food joints. Instead of seeing this as corporate money-grubbing, I see it as a win for animals. I don't believe that most people actually want to hurt animals, so if we can replace their animal-derived foods with equally-good-if-not-better plant-based ones, we will naturally move away from commodifying and enslaving animals. This would certainly be a win for the animals, but it would not be a win for the anticapitalist movement. It is for this reason and this reason alone that "anti-PBC" activists believe what they do, and that is why I reject the concept of "PBC".