Dutch was half naked, injured, and covered in mud. He could have run. He could have fled like a sissy. He wasn't trapped on an alien planet, there was nothing forcing him to stay in place. But he did. And not only did he stay, he turned his immediate area into a deathtrap using plants. He took what little weapons he had and made them into more weapons.
Then he let out the manliest scream in the history of cinema to lure the Predator back to him for the sole purpose of kicking it's motherf**king ass for what it did.
Royce acted out of necessity.
Dutch acted because the density of his balls can only be matched by collapsed stars.