That one song of theirs, "Thats What Makes You Beautiful" is kinda sorta okay. It reminds me a lot of the bubblegum poppy stuff from the late 60's and early 70's. It was pukatronic back then but now it's got a kind of innocence to it that you don't see anymore.
I would never sing it myself but I can see why teenage girls lose their minds over it.

But requesting it of a punk rock band just shows you don't know shit about music.