It does certainly seem dumb, and for all practical purposes it is, but I can explain. (I had to do some ‘bring sports back’ policy writing)
In that situation we’re looking at what can we do, whatever we gotta do, to get the sport(s) back to playing. And one of the things we look at is eliminating any contact/interaction throughout the course of an event that is not necessary to complete the competition. As stupid as handshakes, Jersey exchanges, etc seem after just competing against said person, it’s still a contact/interaction that is not necessary to complete it. So it’s eliminated. And you have to cut the line. If you get into, “well it’s not necessary, but……” then you have a convoluted mess of differing judgements on your hands. Black and white, it’s either necessary for the competition or it’s not. And if it’s not it was eliminated.