Bud Light's stock performance last year would like to have a word with you.
If I hadn't told you the date of the boycott, would you have been able to spot it on this chart?
[1] - https://www.marketwatch.com/investing/stock/bud?gaa_at=eafs&...
https://sherwood.news/business/beer-bud-light-market-share-b...
Budweiser stock did recover, but they haven't (afaik) repeated the behavior that got them boycotted in the first place. It appears that this boycott achieved exactly what was sought.
I'd agree that this is a rare exception, and that boycotts are almost never successful. But this really is an example of that unicorn.