I too have noticed this trend gaining a substantial amount of traction. I guess in recent years, the only accessible romance novels are YA fiction, and romance is becoming a big seller. Though nowadays they're often disguised as adventure books, I think it appeals to a youthful immaturity that some adults dearly miss. You'll often hear adults telling their children to enjoy their childhood and teenage years, because "they're the best years in your life". Maybe it's just them wanting to have a taste of what they used to have? Fleeting emotions, a sense of adventure, both whilst not being to hard on the ol' noggin in terms of the amount of actual thought required to decypher any of the information. People, in the majority, prefer easy to obtain chunks of information, as opposed to articulate and cryptic lines.