They don't in and of themselves glorify war unless they have a particular message which does that, which is actually pretty rare. I can't think of many simulation or sim-lite games which actually impart a specific message glorifying war much more than a game of chess does that (which is after all a primitive war game), or lots of jingoism or nationalism or the idea that war is fun, even if the games themselves are fun.
Military simulations usually don't portray all that much gore, either. If anything, the opposite sort of happens- blow up a plane, ship, truck, tank, or house, you don't necessarily see the deaths of the characters inside of them.
Even arcade ego shooters like Battlefield or Call of Duty- which are usually more close and personal (or games like Doom, which are bloodier), than more sim-like games probably do not glorify war as much as people would believe, otherwise you would see lots and lots more people quick to enlist and request a combat MOS or related field.
I think people's values aren't as simply malleable because of video games, just the same way that authority figures and morality groups have contended that games tend to de-sensitize young people and promotes mayhem and violence, there's no actual causation there- if anything, violent crime statistics seem to have no causal relationship with violent content in games, crime rates can go up or down independent of all that and are probably associated with a slew of other risk factors. You can have a bunch of dudes who never get out of the house playing Xbox wasting other video game characters all day long for their entire lives, but the moment that a patriotic call for enlistment comes, these guys would be the first to say, "No way, hell with that."
What you will see are some individuals- whether prone to criminal behavior, or whether they had heroic or romantic ideals about war to begin with- attracted to violent video games and military simulations, but they already brought that to the deal beforehand. That could be something already related to their upbringing, local culture, or even genetics.
