I think it's really hard to get scared right now but not because of age. It's the fact that you've watched a thousand movies and nothing can scare you anymore. A couple of friends got REALLY creeped out with the remake of The Grudge and they're older than me. But after watching horror movies for 15 years (here comes the nostalgia) I usually don't get scared at all.
The article is ok, I guess. I don't agree with the guy but everybody has the right to make their own opinion.
BTW, the last time I got freaked out was with An American Haunting (please, don't laugh) and I still don't know why. Heh.