I don't think anyone would claim these things are crap or BS, I think it's that these silly problem are irrelevant. These questions are like high school or college coursework, artificial questions designed to reinforce the instruction, but not something that would be encountered in a business setting. Additionally, they tend to gloss over a person's experience.
I may not be able to solve your silly little stock trading problem by myself in a short amount of time, but I am sure that within the normal development environment, I could, especially since I would be working with a team. Or could I? Since this question doesn't look into my ability to communicate or work within a team, you don't know. Also, while I may not be able to solve the problem in 45 minutes, maybe I should talk about the time I dove into an application written in a foreign technology and managed to solve a critical production bug before it could cost the company millions of dollar. But again, you don't know that because you're obsessed with my ability to solve a high school computer science problem.
Different jobs require different skills. Having the ability to code is important, but not nearly as important as teamwork, communication, and the willingness to learn something new. That's the problem with these questions, they are nothing more than smoke screen.