I disagree that tech interviews are bullshit. The biggest tech companies (MS, Google) have invested many dollars, and changed course at least once (remember MS's lateral thinking questions? How many screws in an airplane?) in looking for the most effective ways to quickly gauge whether someone is likely to be a productive SWE. They have done this because they correctly believe that there is a wide range of candidate abilities out there and it is critical to hire as few "lemons" as possible; in particular, not hiring lemons is much more important than neglecting to hire someone who would have been really good. Thinking about it from their POV makes this immediately clear.

I think what you're really saying here is that you don't like tech interviews, which is understandable, but ultimately doesn't amount to either a moral or a technical argument against them.