Just my two cents; I'll make this short and sweet.
"What Makes you Beautiful"
Lyrics: "You don't know you're beautiful, oh oh, that's what makes you beautiful."
...
The girls who don't think they're beautiful are the beautiful ones? So, a low self esteem is attractive? Thinking badly of yourself is sexy?
1D's demographic is teenage girls; the song tells the target audience to stay unconfident and not seek help. That kind of mindset can easily be damaging; it definitely shouldn't be in a song aimed at preteens/teenagers.
Also, unoriginality of the opening bassline.
"You & I"
Lyrics: "Nothing can come between you and I."
...
Should be