It's not that he doesn't get her objections. Han isn't so good a man as that, but he understands. It's just a statement of fact that for them, sometimes there won't be an option. Taking prisoners is a terrible idea, only because they've got too many mortal enemies on the ship already.

"I'm not lookin for a fight," he points out. "I just want us to be able to end one if it comes to us."