Wafflebunny, we don't think of it as a bleak outlook! Goblinville is about goblins going into crazy dangerous places, grabbing what they can and escaping with their lives (and loot) intact. It's not about "winning" in the traditional fantasy RPG way, by killing everything in the dungeon. From the ground up in our adventure designs (and in our adventure design guidelines), we try to instill that monsters aren't just obstacles in the way of the treasure, and that's something important for both our players and GMs to embody.
If the goblins don't kill the ooze, good! That means they were probably smart enough to not go near it in the first place! It also means that it's going to escape, and that's much more valuable as a recurring story in the persistent world of your Goblinville game.