Hmmm, well horror is subjective, and as I've said before, I think the actual issue is that "Dead Space 2" pretty much went down a checklist of things that it could use to call itself horror, without wanting to actually make anyone uncomfortable, or you know... horrified, because in doing that they would get all kinds of complaints about the content. Especially if it was intense enough to get a reaction from genere fans. This is why I think horror games blow chips so much today, the industry is unwilling to do it right due to fear of the complaints. It got to a certain point andthen pretty much stopped, and backpedaled a bit.
To put things into perspective, I don't think many people would be complaining about "Dead Space 2" and it's horror chops, if say "Resident Evil 4" or even the "Silent Hill" franchise had not been made. The issue is that we're now used to games that go this far, and as a result it's not as effective as the first times we saw it. The video game horror genere has however ceased to progress in accordance with the fan base however, so we're largely left feeling disappointed.
I've said all that before.
As far as the helmets go, I think the first offender in video was probably "Major West" in the remake of "Lost In Space". The way his helmet worked was kind of cool looking at the time, and I think one of the movie's more memorable moments, which has lead to wide imitation.
That said, it's hard to really argue with the practicality of these kinds of things in video games. See, for all pretensions of being "science fiction" things like this are largely aping the genere without the actual science/hypothetical science being explained which is what makes the genere what it is. We're dealing with "space fantasy" which is rarley used term where little is ever explained, and picking on one thing like this is silly when you look at all the other things going on.
Truthfuly in a REAL science fiction novel you'd probably have at least two paragraphs (and probably 3 or more pages) explaining how a helmet like that works, or why it's practical within the setting, having derived from other sciences discussed earlier. For example if
your dealing with a setting where they have developed the abillity to manipulate molecular bonds, even on a limited level, things like the cracks might not even be a factor, since once assembled the thing basically bonds into one solid piece in keeping with it's programming. As far as it's storage goes, it could be created by anything from nano-technology, to some kind of energy reactive liquid metal, and despite how it looks, it's actually "pouring" itself into that pattern while being guided by a programmed energy field.... etc...
I could probably come up with a dozen differant science fiction explanations for why his helmet works, and why it would be practical within a given setting. But then again, for all the complaining, ask yourself if you really WANT one. You can give a video game a pretty consistant universe and have things make sense in of themselves, but it involves a lot of exposition of the sort that people whine about. Issac as an engineer would be a GREAT character to play "how it works" with in a setting like this, but somehow I think people don't quite want to get into his head that much.
It's one of those situations where you can't take the "no-exposition that isn't tightly woven into the needs of the story position", or the "no exposition at all, I just want to get on with the entertaining stuff and shoot things" position, and then complain about how jarring the technology between someone's helmet is because it isn't explained, when you'd be whining like a four year old if they ever DID build an explanation into the game.
One of the problems with gaming catering to increasingly mainstream people, is that you wind up losing out on things like "underlying logic" since few people care in comparison to the market. It means that the creator who came up with a consistant universe and explained all this stuff never gets to really show off his universe, or just as often tha nobody even bothers to explain why anything happens the way it does, they just go with whatever seems like it would be cool or easy to insert into the game. A "folding helmet" might just be because it was easier to do that way, than to actually animate him carrying a helmet around with him, or work out where he was keeping it in various scenes. The folding helmet being a middle ground solution to him either never wearing one (or having a super friends bubble drawn around his head), or pulling it out of hammerspace.