I don't get why the Wizards fan would be upset, they would understand... Jeter was a huge rival to BOS. No matter how you slice it, Pierce is showing respect to Jeter who has always been a thorn in the Red Sox for far too long. BOS has been the home Pierce was at for a long time, and wearing that jacket is showing the praise and admiration that Pierce has for Jeter after all these years.
I hope Wizards fans don't get too trivial or frustrated over something so little.