I think some insiders to Nike (not the board but way down the line)....were talked into a situation to help bring the share price of Nike down to the $35 to $40 range (currently at $79.60), and their tool was to convince the Board to go with a Kaepernick contract.
Why? Well...I think the logic is that around one-quarter of the normal customers will now avoid the brand, and it'll trigger some losses on profits (probably to be noticeable in the fall of 2019), after one-year.
The share price will reach a stage where an unfriendly take-over is then possible...in essence, buying Nike at a discounted price because of the customer loss and profits. Who? I can only speculate, but it would not surprise if the buyer off in the distance is a Chinese brand looking to scoop up Nike at a cheap price.
To be honest, I buy an average of three Nike shirts a year....mostly because of the quality. I see the whole Kaepernick 'chat' as mostly a fraud, and you were dealing with a a good but average NFL quarterback. Nike was convinced to make him into some icon figure, and think the negativity will just be a short-term thing.