" Characterizing them as pushing the "omg Terminator" line is just lowering the level of discourse here. That is clearly NOT what they are doing."
Are you sure?
"they are pointing out, rightfully so, that any entity much more intelligent than us, and with a goal set alien to us (like maximization of the number of paperclips in its collection) might as well be out to exterminate humanity"
'AI' means "Artificial Intelligence". The "Artificial" part means it's built by us, human beings, so there it goes the "alien goal". But, oh, you could tell that this AI, being selfconcious and autoevolutive, can develop its own goals... Tell me how that is *not* "omg Terminator" when we are today as far from artificial selfconciousness as we were back in Eliza's day.
And then, the "Intelligence" part means, well, it's not clear what it means but, in the end, it surely doesn't necessarily mean "MORE intelligent THAN US". And even then, one thing is planning for something, quite a different one achieving the intended goal. You see, we are to be considered more intelligent than cockroaches or mosquitoes and we certainly have gone the path of exterminating them (that it would be such a good idea is a different issue), but they are still there.
"because it will do so through simple outcompetition"
Yes, the Secret Council Of Mosquitoes And Cockroaches' fearmongering members also used that argument. But, letting aside the SCOMAC, it is not enough to have the intelligence to, and the goal of, eradicating humankind (both quite unplausible things as of now), you also need a viable interface to the real world, you know, these Terminators were real things, not just ones and zeroes, and that's why they can go overthere killing people.
In the end, we don't need to resort to an AI that it is as of now lightyears of being possible when we have true and tested nuclear arsenals that could achieve the same goal in a very humanly way.
So, yes, everything basically goes down to "omg Terminator".