Hollywood's overwhelming message is clear: Reliable, stable individuals who plan things in advance and think things through are inherently unromantic. Carefree rule-breaking fuckabouts, on the other hand, are POWDER KEGS of passion -- shimmering rare diamonds in a charcoal-and-navy world of boring default people who MUST be pursued and married. Otherwise you'll get stuck with that boring reliable-ass doofus you got engaged to in the opening scene. You know, the worthless normie who never even baited you into stealing a bulldozer or whatever.
The examples are endless. Jason Segel in Forgetting Sarah Marshall is hung up on a ruthlessly manipulative ex (who's also so thoughtful that she bought him Tupperware for the cereal he loves, but then they make her unambiguously suck so BOOO HER). But he learns to love again when free-spirited Mila Kunis forces him to sing at a bar for strangers, then ridicules him into jumping off a cliff and almost killing himself. THAT'S soulmate material: someone who can't read basic facial cues, doesn't give a shit when you're humiliated, and doesn't mind paralyzing you for the sake of brief YOLO.
Rachel McAdams' shrewish character in Midnight In Paris doesn't like walking in the rain. Wait, she doesn't like getting soaking wet at inopportune times? What an un-spontaneous asshole! No one who's mildly reserved about one very reasonable thing could possibly be passionate in other areas of life. Katherine Heigl in 27 Dresses is everyone's "most reliable friend" -- a terrible character flaw! -- who only starts living when laidback James Marsden gets her hammered and they shout-sing at a crowded bar. Good thing, too, because no one who's superhumanly organized and thoughtful could possibly be good at sex, the most basic human impulse.
There's a million more examples, to varying degrees -- Along Came Polly, The Proposal, The Wedding Planner, Knocked Up, Morning Glory, like seven of the plots in Love Actually, any movie where one of the characters doesn't want to dance (BOOOOO!) but another does (INSTA-SOUL MATE!). Being "wild" and "spontaneous" is the only way Hollywood knows how to portray characters falling in love.