Wholesaling - Assignment vs Double Close

[Beau Fugitt]

I've never done a wholesale deal, but I am curious -  why would someone double close over simply assigning the purchase agreement.  I understand why someone may double close if their purchase agreement had an anti assignment clause, or they didn't want the other parties to know they were wholesaling the deal.  Other than that, it seems like a hassle to double close when you could just assign the contract.