Enter password every 15 minutes

Do I really have to enter my password to make a purchase if I have not purchased in the last 15 minutes? I assume this is some convoluted security idea and not just a way to waste my time. Is there a way to disable this?

I sort of understand the reason for my phone (although, I am not sure who would find my phone if I lost it, and decide to buy apps for ME!), but I am pretty sure my desktop is not gonna get lost. I am pretty sure no thief will break into my house, boot up my computer and start purchasing apps for me.

Bruce