I can appreciate your anger over this aspect, but for me it was a minor issue because I felt it made no difference to my buyers whether I was obliged to use one method or the other, or both. And it was really only a small inconvenience for me. As long as my buyers can purchase and pay in whatever way suits them, I'm happy. I see it mainly as a service to my buyers, not as a forced disadvantage for me. I understand that not every seller will see it this way.
A little fewer than half of my buyers still pay with Paypal, the remainder through Etsy Payments. Not everyone knows about, or wants to use, Paypal, so I've never considered it a bad thing that an alternative was made available.
Now eBay's plans may be different, and where they would cross the line for me would be in usurping my role and responsibilities as merchant. My own view is that as long as sites don't actually confuse buyers by presenting themselves as the seller/merchant in the transaction, as long as the payment process is easy and secure, and the site isn't charging an exorbitant fee for handling the cash transfer, I'm fine with being obligated to use it as long as I can also offer Paypal.
After all, for many years eBay virtually imposed Paypal on sellers as the preferred, if not solely acceptable, payment method. And remember that eBay actually owned Paypal during that time. I don't see this as very much different from Etsy's requiring sellers to use their own in-house payment system. The one improvement clearly would be to permit sellers to have their own money accounts within that system, as Paypal has, which could be used to purchase other goods and services. But I don't think Etsy has any desire to run a banking site. Obviously neither did eBay, judging by its recent disposal of Paypal. Which does tend to give some credence to the belief that eBay may be looking for other possibilities now.
