[heedlessly3]

I think not giving candidates any feedback has to do with companies being lazy than fear of being sued.

If you have 50 candidates do a takehome assignment, then you will need an engineer to do code review and write comments on everything. Whereas it's easier to execute the code and have an engineer glance at the code quality. Their time is better spent looking more deeply candidate's who move onto the next round. I'm not saying it's morally right, but it's just more time efficient for companies to do this and that's how the power dynamics unfortunately work.