Being punched has a significant physical impact and a significant symbolic impact. Being spit on has a significant symbolic impact, but a relatively small physical impact.
Symbolism only works if you let it work. If someone spat on me, I might feel hated, or denigrated, or shamed. However, if I’m secure enough in my motives for doing whatever it was that got me spit on, then I can not let the spitting get to me. I can trust that other people can see it for what it is. Or, if they think of it as an issue of manhood, I can take another action—a delayed action. I don’t have to respond right away.
Punching is similar. But it hurts a lot more. It also raises manhood and strength issues. But nowadays, people know that mental strength is much more important that physical strength, so it is not always necessary to respond physically. That depends on what culture you come from.
I’d rather be spit on.