I think they were trying to make an equivalent argument to the questions around the existence of plant-based “meats”. That line of reasoning usually goes “why create a meat-like ‘concoction’ from plants rather than just eating delicious plant products themselves? Why do we need products resembling meat? Just eat a plant-based diet.”
I understand now that these products aren’t for me, and aren’t necessarily for those who are comfortable working directly with plants in the kitchen. They also provide an easy off-ramp from a more meat-heavy diet. Beyond Burgers are akin to vapes for those struggling to eat less meat.