I really hate it when a character I like is killed off just for plot development.
I've even stopped reading a series because people were killed off through sheer stupidity, just to demonstrate how dangerous the situation was. Talk about red shirts - that got really old, really fast.
There is one double episode in Stargate SG1 I refuse to watch, and another in Atlantis. Both episodes killed minor characters, and left me so devastated I almost stopped watching the series. The main character death towards the end of the 3rd season of Galactica, stopped me cold for 3 days, and I mean I did nothing of consequence for 3 days, as if someone close to me had died. I did start watching again, but only because I bought the entire series at once, and there was still 1 season to go. There is also the major character death towards the end of Trek NextGen season 1, which also will never be watched again. In fact, I never forgave them for that.
I believe one has to be careful with major characters. Killing them off just for plot or character development can be a major bombshell in the readers life.
If you intend such a thing to happen, because your MC needs it, then you need to make very sure that the trigger is a minor and forgettable character, who is built specially for the task, with no real reader engagement. Or that character has such a major character flaw, that everyone but the MC breathes a sigh of relief when gone.
I cant see why a love interest cant be written in a way where the reader actually wonders why the MC is with this person anyway. So when the person dies, the reader is more than happy to see them gone.
On the other hand, what is this obsession with killing characters? Yes, its a war, people die. But when your readers love your characters, killing them is dangerous. Why cant they simply be promoted and transferred unexpectedly, and then a reason put in place why they cant communicate.
In the case where 2 people go into stasis, and you need to remove one of them, why not have something change in the person which ruins the relationship rapidly. The one you dont want walks away, and leaves the MC with the exact same emotional state of a death. At least the option then exists to bring the loved character back later on in a different role.
A character who leaves is easier to handle than a character dead.
From what's been said, I think I'd fall into the group who would have a hard time getting past the death of a loved character. Even a damned good reason, which there rarely is, doesn't go down well. It always comes over as being a writer killing someone because that's the easiest way of doing something.
The challenge is to induce the same effect in your MC as the death does, without killing anyone.
Edit: Elizabeth Moon did this in the Vatta series. In one paragraph, she kills the majority of the minor characters she had spent 4 books building up, just to provide a reason for moving the MC. And that one scene in the series, destroys the series, imo. Sure, its the last book, its a war, people die, but it was so gratuitously done, it was devastating to the reader. Given half an hour to think about what she was trying to set up, I could have provided several ways of doing it where no-one had to die. Killing was the easy way out for a writer locked into a thought pattern.