You take your car to the shop. They tell you that your water pump needs to be replaced. You decide not to replace it and keep adding fluid to your radiator. When your car breaks down, do you blame the auto manufacturer for a faulty water pump? How about the repair shop for not insisting that you need to replace the water pump?
If a POS vendor tells a retailer they have to cut support until a vulnerability, do you think the retailer insists on continuing to use that payment source? I guarantee they’re going to insulate themselves from liability, to hell what the public thinks.
I’m just saying that there are likely technical reasons for the change. It’s not done to spite you. It’s done to protect them.
If Walmart really cared and wanted Samsung pay still, they would have it. They aren’t your run of the mill retail client and thwir POS provider is not going to be allowed to go in and add or take away payment options on their own particular whim or preference.