Assuming the homework assignment is happening in the hiring phase after the initial screenings, I don't buy this. Getting to that point means it's time to show

Assuming the homework assignment is happening in the hiring phase after the initial screenings, I don't buy this. Getting to that point means it's time to show them why they should hire you, and it's going to take up your time whether you do it in person or "asynchronously". If they give you the opportunity to spend those couple of hours at home rather than at a whiteboard in their office, but you don't care enough to make the time, I don't know why they should care enough to hire you. If the "homework assignments" are just a scheme to get work done for free, or a competent engineer's time is not set aside to review them, then that's a different story. But as a fair test of programming ability, administered in good faith, I don't see the problem, and such a test is important.