Where are they now - Andy Hall

Well, the road to success just got tougher for Andy. The Eagles just signed Jeff Blake, which means Hall will likely end up on the practice squad for next season and not the active roster. That also means a significant pay cut. My question - if a team drafts a player and elects NOT to sign him to the roster, why should they retain rights on the "practice squad"? Why shouldn't these guys be able to test the free agent market with other teams? Or is this actually a good thing for recruits? I can't tell.