It will have no motivation to prevent you from pulling the plug. Human level intelligence is not the same as animal instinct.
There has been some attempts at researching the question of how to design a intelligent system that is "corrigible" = willing to allow humans to change the goal it is set to optimize. This is unfortunately still an open question where no great solutions have been found that seem to be reliable when faced with a highly intelligent and capable AI system.
If you are interested in reading more, a few relevant search terms are "Off-switch game" and "corrigibility".
There are certainly ecological and mimetic niches where pro-social behaviors will improve fitness. But it’s also certain that anti-social (defect/dominate/parasite) behaviors will improve fitness in many niches.
Alternatively an ASI can ally with a group of humans to whom it can credibly promise wealth and power. If you think there is a baby machine god in your basement that is on your side, you’ll fight to protect it.
In this scenario, pulling the plug is a matter of turning off power to the data centers it runs in - or simply disabling the one mode of external communication it has.
AI feeds on data. If it can make you a million dollars air gapped, you'll be able to make a billion with it plugged in the net with it manipulating data.
If you solve alignment, the regulatory nudge required for folks to use it is probably not that big; let’s be really pessimistic and say it’s 10x the compute to run all the supervision. It’s probably mostly criminals that want the full-unaligned models, and so most entities can agree to the spend.
In the air gap case, I’m pretty confident that it is many orders of magnitude more profitable to run the “unsafe” / non-airgapped version. The utility of baking AI into everything is massive. Maybe in the best case you can have your airgapped ASI build provably-safe non-AGI tool AIs and capture much of that value, but I’m pretty skeptical it’s safe to transport anything that complex across the airgap.
So the alignment research path is more sustainable since it requires paying a much lower “safety premium”.
But I’m all for pursuing both, I don’t think they interfere with each other, quite the opposite; taking either one seriously reinforces the need for both of them.
Another advantage of the alignment path is we can meaningfully make progress now. It’s really hard to get people to agree ahead of time that they will run their AGI in an airgap.
But even if we ignore that, note that nobody is building their systems this way, and nor will they without extremely draconian laws requiring it. An airgapped system is substantially less valuable than one that is connected to the outside world.
I take the question “why can’t we turn it off” to refer to the actual real systems that we have built and will continue to build, not hypothetical systems we might build if we took safety risks very seriously.