Because an invincible, infallible love interest is boring.
Please feel free to add Pot Holes to the description as needed.
"Frollo might be the most overtly sexual Disney character period, and yet he's even more squeamish about sex than even girls are taught to be. So, he's kind of relatable. He's tortured by his physical desires... We like tortured, I guess. Even if it's attached to a decrepit old man with a gaunt French nose. Also, he kills people. He's a bad boy."In this trope, a character is found attractive because they're vulnerable or flawed. To be listed here, this must occur In-Universe or be a Discussed Trope. Vulnerabilities are attractive. Many times, people enjoy a "project"; they like a guy who seems like he has something good just under the surface and just requires that special someone to draw it outside, or they like a girl who depends upon them and makes them feel Rated M for Manly. Maybe part of the appeal is trying to change them, maybe part of it is the desire to feel needed, and maybe part of it is being drawn by the allure or mystery. After all, if the other person seems like they'd do just as well (or even better) without you, what's the fun in that? Another term for this is "accessibility". Super Trope of All Girls Want Bad Boys, Tall, Dark and Handsome, Ugly Guy, Hot Wife, Hot Guy, Ugly Wife, Ill Girl, Distressed Damsel, No Guy Wants an Amazon, Weakness Turns Her On, Dating Catwoman, Defrosting Ice Queen, Moe and I Can Change My Beloved. Sometimes overlaps with Women Are Delicate and Men Are Tough.
The Nostalgia Chick, on why Frollo managed to qualify for her democratically-elected "Top Ten 'Hottest' Animated Guys" list.