If you're Morgan Rogers, you are at a point in your career where you might still not make it as a professional. You have maybe 2-3 years to impress somewhere before getting released, and if you do you might not be picked up by another club.
In those 2 - 3 years, you could play for West Bromwich Albion earning £500 a week, or you could play for Manchester City, earning £20k a week. For the player, this is a no-brainer, as just three years at City could set you up for life, even if you don't make it. Even if you do get released by City, you can probably get picked up by a Championship club - which we currently are. So it makes sense.
The problem is the youth transfer system is broken, and needs fixing. But we haven't got any interest in fixing it because we can cherry-pick from below us for peanuts.