Well first of all, all of those films are way better written than any metal gear. The way those films handle violence and characters instead of glorifying it. The beach scene in Saving Private Ryan never feels like objectification or glorification of something as horrific as war. They also didn't feel shoehorned into the film in an attempt to seem more mature than they actually are. There's no pointless monologues and the messages are not shoved in the viewer's face. They accurately portray war because the moments they show those horrors aren't for the sole purpose of establishing a cartoonish villain as evil and making the viewer despise them.
That's not why I brought those up. They are a closer approximation to what he is intending, rather than the economical cinematography of Horror which you delineated as being "more clever" and more appropriate because it didn't show stuff. I'm just pointing out that wouldn't work in this genre.
Whether Kojima is successful is down to you (I suspect you don't like his work much so I can't work out why you even play his games), but I feel you are misreading his intentions. This isn't him tackling subjects apropos of nothing, he's touched upon most of these issues in one form or another throughout the series (Child Soldiers in MG2, Rape in MGS3, Torture in MGS1; Christ, he made battlefield surgery a
mechanic in MGS3!). The new technology is allowing him to depict them more accurately. Can you imagine Saving Private Ryan rendered in 8 bit? Wouldn't be as effective, methinks.
If you think that those horrors are there
only to depict Skullface as a baddie and not as a broader statement, then you may be missing the point.
Also, everything on-screen, be it in a film or a video game, is objectified and glorified in some way, whatever the message may be. That's always been the irony of graphic anti-war films.
Saying that viewers don't actually know what war is like is very insulting to the movie going audience that's been exposed to this kind of subject for more than fifty years.
What the hell? Saying that viewers actually know what war is like because they saw it on TV a few times is insulting to people who have actually been caught up in or fought in one.