On the other hand, it still seems horrible to kill people by remote control. Supposing it becomes possible to very, very precisely kill exactly who you want, from far away, with no judicial process, etc., is this good?
War should be painful for both sides, because if it is not, what stops us from engaging in it?
There is a rational sense to be outraged over more precise weaponry: precision incentivizes super-states to use it more, which in turn incentivizes things like surveillance. At the long tail of this shift of incentives one can see a a quite spooky/sinister picture emerging.
What is new is the use of signals intelligence to choose whom to target in a non-combat zone. I think that's the novel piece that should horrify people.
In the longer run, being able to take out who you want without killing innocents modifies the moral calculus. You don't have to justify the turpitude of your target against the lives of innocent bystanders.
So eventually the question approaches: how do you hold steadfast moral red-lines regarding the use of such weapons as PR costs and blowback approach zero?
This is only possible if the killing happens in total secrecy. The court of public opinion is a judicial process, and an important one, despite having only informal procedures.
(Edit: this happened to be submitted earlier today:
It's like suggesting laser guided bombs are worse than unguided bombs.