The Goddamn Lava Control Valve

Forget how this thing works for a second, what I want to know is, why the hell did we just gung-ho turn it on, and never even think about turning it back off (the game literally won't let you lol)? Like, the digadigs went through all this work to make this thing, then turned it off and did their damndest to stop anyone from getting it. Clearly, stopping the lava creates some sort of pressure build-up situation, and though, since the valve still works, it probably didn't lead to an eruption in the past, I'm sure it's a ticking time bomb as we speak. So good job, everyone, we just got all those Dinurians to come hang out and now they're all going to die.