You think those Wal-Mart folks would hesitate to drop your product from their shelves without giving you a reason? You think they are shy about making their suppliers sign a scary one-sided contract and then holding them to it?
Actually, yes I do hesitate. WalMart makes its demands up front. You know exactly what you're getting into when you sign with Walmart. It doesn't change its behavior after you've signed the contract, or make capricious decisions. If something needs to change, Walmart lets the supplier know, and why it needs to change, and how it needs to change. Apple doesn't even give you an email.