A ground-acid nerf seems like a great idea. There are plenty of ways to counter ruptured spitters though, especially in choke points, but most marines don't use them.
Arc rounds are one, so are claymores, prox. mines, Smartguns, and the melee function that few players really use. If you're a good shot, you can 1-shot them with the upgraded pump shotgun as well. Or you could, like, split up and not all run into the acid puddle to revive your buddies.
Nearly every Escape game I've played, the only way to win as the Aliens is to charge with Spitters + Rupture. The marines are simply too powerful, and you can jump them with wave after wave of soldiers/lurkers to no effect.
I really don't see why everyone has so much fun with it. Not nearly as "realistic" as TDM or Extermination. In my opinion, Extermination is the best mode and brings you closest to that Aliens movie feeling we all want.