5. Acid is weak, and sometimes doesn't even affect certain materials. Heat affects all materials, especially you.

You assume that the liquid is acidic. For all you know, it could be basic. Yes, that's right. Bases can be corrosive, too. And besides, that is a pool, not a spritz here and there. Besides, the fact that it kills you is almost certainly for gameplay, not realism, because if you got trapped in a pit it would suck, and because you would be campy as **** if you could just sit down there shooting at things that have no idea that you are there. Hell, we don't even have water yet, so even having it act as water would cause problems. Realistically, there are some materials that aren't even affected by most acids. Furthermore, to actually kill you the acid would have to seep all the way through your dropsuit and into a vital organ or something. Heat can seep through materials that can withstand it. Acids, being matter and not energy, cannot.

It is such an asinine idea to assume that acid-based weapons could ever work in actual battle. They cannot, which is why militaries have never used acid on an appreciable scale (compare that to flamethrowers, if you would). Why? Because acid cannot kill you quickly on contact. Heat can.

And I never said that acid cannot kill you. I said acid was weak. You know what else is weak? Hitting someone in the stomach, but if you do it hard enough or do it enough times, you can kill them. You can even do that in Dust, despite our heavy duty dropsuits, or perhaps because of it.