Here OP, let me make an analogy to explain why Apple is not entirely responsible, only partially, for Foxconn.
Why should we let the OP (or any other poster) abdicate responsibility for their supply chain? If OP chooses to work with a grocery store, then OP is on the hook for ensuring the grocery store is a reputable and humane supplier.
Or is it okay to let a poster like OP accrue the benefits of outsourcing (i.e. not having to have a farm or barter with farmers directly) while ignoring negative consequences (i.e. environmental damage, inhumane working conditions, etc.)?
See how silly that sounds? Now, in reality responsibility scales proportionally to percentage of gross sales you make up for your supplier. OP to his grocery is a many to one relationship, giving him little responsibility. Apple to Foxconn is a few to one relationship, giving apple more, but not total responsibility. However, when a supplier has only one customer, that customer has total responsibility.