There is no reason not to be careful because you don't want to buy a new one.
I agree 100%. But not letting your friends "touch or handle" your phone goes a bit beyond being careful. Yes, I try to avoid dropping my phone like the plague. Every time I get in and out of my car I check my lap and pockets to make sure it won't fall out. I don't leave it sitting on a table when I walk away to throw out some trash. I try to be diligent with it, but at the end of the day, it's just a phone and if my friend needed to make a phone call, I wouldn't think twice; if a friend wanted to try out JawBreaker or Auroa Feint, I wouldn't think twice.
No one is saying you shouldn't be careful. Certainly not me. But there's no reason to be extremist. That's my point.