why does microsoft always ask for exchange password on apple products

Please help us help you by giving us some context. What Apple device? The iPhone in your equipment line? A Mac computer? Does the message appear when you start the computer or when you try to open an app?

You pose what should be a great question for Microsoft support. However, if you or your company use a Microsoft Exchange server, that log-in message will be a Microsoft message and is proper.

If you do not access a MS Exchange Server and bought a pre-owned device, it could be an organizations's "managed device" that was never properly prepared for resale. It wil never be fully functional for you until it is cleared of the management software and properly reset. Only the seller can do that, not you, not your fellow end users her, and not Apple.