In the case of Dad, it's not that he doesn't understand why they would have flamethrowers, he just feels the need to point out that it's rather stupid that they use them when they have other means to destroy stuff that are less bombastic. Rule of Cool need not apply.
You know how in Austin Powers, Dr. Evil is talking about the slow, horrible, and easily escapeable way he's going to kill Austin, and Scott Evil says they should just shoot him in the head? My dad's Scott. It makes sense, but where's the charm?
I like smart films, but occasionally you just want to sit back and watch something where the only rule of logic is, "It works because it's more awesome this way!" Okay, so realistically a mech that size would collapse under its own weight, and there are forms that are more practical for battle than humanoid, and remind me again why it can only be piloted by angsty 15-year-olds? But the story's good, so just shut up and watch.
