I shop at HEB, and buy both salted and unsalted butter for their specific uses. I can confirm that I’ve used the wrong butter multiple times because of this, and I always curse them for it. That said I still love HEB

“They won’t buy both. They will never know.”

OP:

Think of it like home/away colors on sports uniforms. Home = blue with orange accent, away = orange with blue accent.

So after some googling, apparently this is a VERY widespread practice spanning multiple brands, multiple manufacturers, all around the US; but I can’t seem to find any explanation. It can’t just be industry-wide madness, right? …Right?