It's so they can put their FREEZING COLD hands on your back, WITHOUT your permission most of the time. Or maybe they'll wrap their arms around you for a surprise hug...but wait..it's not just affection..oh no...because BAM, they've stuck their ice hands up your t-shirt and onto your stomach and you're like "....oh my god..", and maybe..maybe you let out a little scream..like a little girl...
So yeah...that's why OP..that's why..