Not just special teams in general, but the contributions of a player like Janis in the play mentioned, when he didn't come close to actually making the tackle, but forced the runner to turn up field into a half dozen other Packers in a limited area of the field, who easily made the tackle for a very modest return. It's easy to look at the number of ST tackles and wonder how much contribution there is, but a player abusing a couple would be blockers to cut the field width by 2/3 is worth quite a bit even if he doesn't make the tackle.