In front of New Life Base...
"Is that necessary? We've come in peace. Look, we aren't even armed" Muku tried to reason with them. Using a reason that wasn't reasonable anymore.
The guards just looked at him like he was an idiot. Wtf did he mean that they weren't armed? Who didn't know that modern weapons didn't work anymore? Hell, even if they still worked at that point, many humans would still be a lot more dangerous than the weapons.
So, for Muku, who had "walked" there with two girls through an unknown number of beasts, to say they weren't armed. Trying to hint at their harmlessness, was super shameless. Who in their right mind would believe such a thing?
For that reason, the guards rolled their eyes at him without budging. Their silence says, "They take their veils off, or you aren't entering".