Cutesy Name

Why do humans like to change our names to something cutesy? I mean, look here, we are mature males (my group of friends are mostly males), and I usually cringed when I hear cute-cute names on them. For example:
Joey (that's me) - jojo, joey-baby, joey-sweetie, joey-kun
Scuba - Scoop-scoop, Scupi
Tommy - bunny (rofl, tommy is a bunny???)
Rafv - Raf-fi-fi, lala (rofl even harder)
Herbie - e-bi-bi, e-ba-dy (hiak hiak)
by the way, I realised Jaffe has a different surname from his humans parents (Fun-Graham).. cos I hear his mummy called him .. Jaffe-YEO.. all the time!

Jack, hasn't got alot of cute names except for Jack-Kun, which is not quite cute, simply because, well...... he is just NOT cute! hiak hiak hiak