As the leader of Block B, he has to be there with the plan. As an icon of what Block B stands for, he has to be energetic. As the Troll King, he cannot show that, for a moment, he is tired. 

I'm not dissing on Jiho or any BBC out there, but we have to remember that these artists we watch on TV are not gods or anime characters. We usually only remember that, when they get hurt and for a moment, they're human again. This is a bit hypocritcal, because I write fan fictions, but they have weakness and they can't always be the trolls that we think they are(: