You do realize it wasn't people saying that it would definitively destroy the world, but were simply pointing out that nobody knows if it could destroy the world.
Personally, with our level of technology, if you're working on something that will potentially blow up the world, Wouldn't it be alot more comforting to conduct the experiments somewhere a little 'safer' for the rest of us... like on the moon?
I'm not fully serious here, but I'm just saying that if the science carries that type of risk, but is that important to the future of our understanding of the universe... that it might be prudent to conduct the science in a way that, should the worst happen, that there would still be humans around to try keep sciencing beyond that failure?? Unless opening up some black hole / singularity that would consume the planet would be a 'success', is it really worth it if there's noone left to benefit from the experiments?
There was absolutely no possibility of the Earth being destroyed. Even the most talked about method of destroying Earth, by generating a black hole that swallows it and us up, was based on BS. A black hole of the size that can be theoretically generated by the LHC would not last more than a couple of microseconds before evaporating. Those against the LHC were opposed to it only because they chose to be ignorant.
The ghost of Jack Kevorkian for President's Physician: 2016