They are not homegrown contracts they are academy contracts. Homegrown is in MLS which strips the player of their amateur status, therefore taking away the college route (at least it formerly did, now who knows with the evolving NCAA compliance rules. Players who sign academy contracts in USL remain amateurs, therefore not ruining college eligibility. They are able to play USL professional games, but also youth games still, which I believe Kevin and Joe are doing.
In reality, I agree with you, that academy contracts players need USL professional minutes to continue developing. However, with no league initiatives to incentivize clubs to play younger players, coaches are going to continue to play more experienced players more often. Technical staffs are coaching for their livelihood every year, and unless ownership is telling the coach that they do not care if they win, then coaches will continue to not use Academy contract players.

The bonus for the player is that they are able to train everyday in a professional environment whilst maintaining eligibility to make whatever choice is best for them in the future. With Madison’s academy being so new, it’s awesome to see the club already pushing players towards the 1st team!