The only problem with horror today is the reliance on gore and the lack of emotional investment in any characters - stuff that has always been a problem for this genre since the 70's and 80's. There are plenty of examples of horror being perfectly fine in this era, and any critic insisting otherwise is only focusing on the mainstream commercial stuff and not independent films, and isn't a real critic.
I think the 90's were the worst decade ever for the horror genre. It's gotten waaay better since then. The 90's consisted of zero atmosphere, a focus on teenage high school angst, crappy and forgettable scores, crappy soundtracks with bands like Creed... It was just generally awful. Scream, I Know What You Did Last Summer, Urban Legend, Valentine... It was just a total bummer of a decade. It wasn't until the decade was wrapping up in '99 that we got Sixth Sense and Blair Witch.
I think 2000-2015 has given us some of the best horror movies EVER, easily. But the 70's and 80's are still the two best decades, in my opinion. That whole era of Stephen King, John Carpenter, Wes Craven, Clive Barker, Sam Raimi, George A. Romero, Dario Argento, Lucio Fulci... we'll never get a revolutionary group like that ever again. That was like a nuclear bomb of creativity went off in the film industry.