Imagine every part of your body represented different assets; your head is your automobile, hands your home(s), feet your boat, etc.  Of course you can cover each of them separately (i.e. hat on your head, gloves on your hands and shoes on your feet), but what do you do in a downpour?  I would take out my trusty umbrella. 

In insurance it is much the same concept.  You can cover all your parts separately and give yourself an extra layer of protection.  For a minimal annual premium, you'll get a blanket of extra coverage.  Avoid the downpour and get a quote now!