The problem with death in games is they expect you to care about someone you know nothing about, have no reason to be attached to, and possibly don't even know the name of. It's not how much death has happened in the story up to that point, it's "why do you care?"
I'm going to use a comparative example here. In CoD:WaW some nameless guys in the American squad ultimately end up dying in scripted events, but the thing is that I don't care. I don't care like I do in CoD4, or even Black Ops when their important characters die, because unlike in CoD4 or again even Black Ops (which I don't think is a good game at all, mind you) WaW doesn't take time to establish the group dynamics or who individual people are, so I never got a real sense of having a team behind me like I did in other CoD games. They do succeed on the Russian side, I guess, but on the American side, you seem to just have a team of easily replaceable dudes who you don't really get attached to at all.
On the RPG end of things, I've been playing a few Final Fantasies side by side, and I can tell you that sheer quantity of death doesn't make it lose power. FFIX. A lot of nameless NPCs and entire towns get wiped out over the course of the game, but you still care because a) they take time to establish the places that get destroyed so you get attached to them, b) the characters care, and their emotions at seeing people die horribly are very tangible, and c) because they use very brief cut scenes or dialogue to establish the people who are dying as people, and, guess what, a lot of those people you talked to in Disc 1 are never coming back. This makes it effective, at least for me.
Compare that to FFX. There are scenes where large places and loads of people get wiped out, but I never found it anywhere near as effective as in FFIX, because I never bought them as being tangible places. A lot of these places were destroyed before I ever even got to them. They killed one minor NPC during one of Sin's attacks, and had his friend grieve over him, which kind of worked, but, otherwise, it's just not as effective. I mean, yeah, the death and destruction is kind of a morose thing, and you get that from the Sending Ceremony, but the difference between FFX and FFIX is essentially one using death and destruction as a means of reminding the audience that the stakes are supposedly high in order to make them care, whereas the other is more like making you care about the places you visit so as to make what happens to them completely unexpected, and make you think, "Holy crap, anywhere could be next!"
So, really, the effectiveness of death isn't anything to do with quantity, it's more how much you care about the individual person or place that's being attacked. No one is going to care about death if they don't have any reason to care. They don't even have to be established characters at all, it's just that the audience needs to be able to empathise. It's like the difference between seeing CGI people or stock characters getting killed in disaster movies without any real weight attached to their deaths, and seeing just a handful of people you've never even seen before individually dealing with their terror and grief in Titanic. It's not the death itself; it's how it's handled.
EDIT: Or allow me to use another example. The destruction of Nibelheim in FFVII kind of suffers the same thing FFX does. It doesn't really make you feel, "Oh, God, people are dying!" but rather the scene's effectiveness is to establish how powerful the enemy is, not to make you feel the deaths are tragic in any way.