I mean that guy is being an idiot, but it's also not quite that simple. There is still more and less ethical consumption. A fairphone is more ethical than an iPhone, and pointing that out in good faith to someone complaining about Apple's behavior seems entirely fair.
It's not a complete fallacy to point out that someone is consuming something less ethical when they have a better option. Obviously it's impossible for anyone to do this with literally everything, but absolutely you can avoid Starbucks because of their treatment of unions, and frequent a local coffee shop instead.
Granted this is mostly assuming two people having a good faith discussion, which on the internet is infrequent lol.
US supreme court sides with Starbucks in union case over fired employees ( www.theguardian.com )