The Quiet Ones trailer: are the 1970s inherently scary?

What is it with 1970s retro horror lately? I know the fashions were pretty terrifying back then, but that’s about it. Is it that that decade was when recording equipment got cheap enough and portable enough for ordinary people to goof around with, and so they started filming whatever they could, so there’s a record of what they did? Or is it just about lending a generic sense of history and hence — perhaps — authenticity?