I do too, but you're also not factoring in the people they will gain from this. You honestly don't think for every one that is stupidly burning their NIKE gear, there aren't others buying up for the same reason? Which I imagine has been factored in with their analysis.
Their analysis is probably just bad then. Companies screw up all the time. The rating agencies rated mortgage backed securities to be triple A when they should've been Z- 10 years ago.
Are there that many people out there saying "Nike supports Kaepernick, I'm with them more than ever!" Seems doubtful. If it was such a good idea, why not do it a year ago when he was more culturally relevant?
Meanwhile you got sites like Breitbart, social media, other sites I'm unaware of mobilizing people to boycott. Yeah, it'll likely fade eventually but like I said in a previous post, the people who loathe these decisions can mobilize via the internet now rather than just say "Fuck Nike and kaep" and shut off their TV.
I think the sum is negligible but I'm surprised people actually fall on the side of thinking it was a good move.
(And overall I care about all this as much as you do so not invested in the outcome either way. I guess it would be cool to see a company beaten down over their faux-activism but wouldn't hold my breathe)