Hmmm, interesting. To be honest though I think half the point of such studies is that people are rarely honest about what scares them. Something like "Dead Space 2" is the kind of somewhat goofy game that looked at objectively shouldn't be considered scary, especially to a genere veteran, but then again when you measure things scientifically and find out what people are really thinking, you get a differant result.
To be honest the results shouldn't surprise anyone, given that you have a lot of marketing people behind the production of games like this, who draw on all kinds of data similar to this study in order to determine the path of game design, a fairly big budget game like "Dead Space 2" probably drew on a lot of experience in being put together.
There is also the whole "nerd culture" aspect of things, especially among the hardcore. That is to say the tendency to want to say "this kind of thing isn't scary" and sing the praises of more cereberal horror because that's what everyone else is doing... but really, in the end that's not what's getting under their skin.
Another point to consider is that actual fans of horror are fairly uncommon. Most people who are, are kind of poseurs about it. These are the guys who lionize Steven King and those who emulate his style to an extent... like oh say "Alan Wake" but at the same time Steven King really isn't scary, especially not anymore. His entire "the best horror isin the mind" doctrine made him popular with those who like the idea of horror, but don't actually want to be scared or made uncomfortable. There have been some analysises of his work done in the past, similar to this one over a period of years, with him and other "pop horror" writers being compared to more fringe writers.
However, it's also noteworthy to point out that being a limited audience, successful horror is never going to be as popular as the stuff that seems like it should be horror, but is really little more than a suspense piece when you get down to it. Within things that actually qualify as horror it can get into some pretty serious debates between what's good, and what's bad.
The whole point of this study is that a lot of people will sit back and go "lol, Dead Space isn't scary, it just has a ton of gore" then ranting about atmosphere, which honestly Dead Space is actually oozing with, and so on, and then maybe going on about how it only has jump out scares. What this study shows is that this is the game that actually likely "got" those people and thus breeded the kind of resentment you see from non-horror fans when they actually run into the real deal, and try and disguise as something else so they don't come accross looking like terrified little girls.
It would be interesting to see what would happen if they were to pay a group of people to play through say the first two Silent Hill Games which are lionized as being "the most terrifying thing out there" and say the two "Dead Space Games" in their entirety under this kind of study. It would be a pretty long term project, we're talking about 20-80 hours of play time here.
I say this because to be honest while Jaded to the point where neither really "got" me, I honestly think Dead Space probably did a better job of actually producing a tight horror experience, where Silent Hill rarely progressed beyond the "creepy" level. Both being quite good games, but if your going to rate them as horror, well I think Silent Hill is more an exercise in surrealism than actual horror. Truthfully I think the two worst reviewed series installments, "The Room" and "Homecoming" actually came the closest to being actual horror games, and sometimes I suspect that is why they are among the least popular of the bunch.