Teams like McLaren and Williams, even the original Force India started purely as racing teams - with racing as their primary business; never mind the spin-offs, they are primarily racing teams. That can be said about Haas as well. Ferrari, AR, AMR, Renault and Mercedes are all originally automotive companies who came in to improve their road car brand image through racing success; and to use F1 to develop their tech prowess and to maybe test innovations. Racing and F1 are a natural fit for them.
But what is the primary purpose of RB and AT? Why are they in F1 in the first place? How do they fit into F1? They are here because of their brand positioning and marketing strategy! They basically use anything extreme - from record-breaking acrobatic flight teams and motocross stunts as avenues to put their brand on, so that people will associate everything extreme, risky, daring and awe-inspiring with the RB brand. F1 is one of those many marketing gimmicks for a mediocre drink. So, Marko can afford to have no sponsors at all; RB marketing team will keep bankrolling the team as long as it benefits the brand.
For every other team, having sponsors is crucial for their survival and success. By ridiculing McLaren and Zak, Dr. Marko is simply admitting their primary objective is to run expensive signboards to promote their own brands.