How can you be discriminated on a technical level? Is there even a case of a candidate who sued a company at a technical stage we are aware of? This seems like a weak argument considering the hassle of time and potential legal fees, especially for someone who is looking for a job? Although I could understand why a candidate would try to bring a case like this in the US.

Anyhow, it's not even the feedback the problem, it is that I have enough work experience to understand some of those startups seem to operate on a thin line between what is a technical assignment related directly to their core tech and getting free consultancy. The least they could provide to candidates who have involved time is what was expected.