I’ll take this perfect opportunity to say how disappointed I am about however one would describe this situation with Colin Kaepernick and Nike.
Yes, selling out is actually a thing. It never went away. And it has always had the same significance.
Pop culture for decades seems to have decidedly and wholeheartedly endorsed selling out, cashing in, etc., making it seem okay or even necessary. Well it’s not. Almost nothing is absolutely necessary.
Everything you do is a vote. Perhaps the most meaningful votes these days involve how you spend your money. When you spend your money on a product or service you are not merely conducting a transaction. You are materially supporting the ability of the entity with which you are conducting commerce to sustain itself.