SaucyJack - OK, I accept your point that you wouldn't replace everything - but could you afford to replace the essentials all at once?
In the kitchen - washing machine, fridge/freezer, oven, pots, pans, crockery, cutlery, toaster.
Lounge - a basic suite, a table, a TV, some toys for the children.
Bedrooms - a bed each, bedding, clothes, a wardrobe/chest of drawers.
Technology - laptop/tablet/PC, games console, Sky box/freeview box/dvd player.
Carpets and curtains throughout the house.
Dh and I tallied it up in our heads last night and reckoned, that, just to outfit a basic household with the essentials, you could be looking at several thousand pounds - maybe £10,000 or more.
And don't forget, in the event of a catastrophe like a fire or flood, you would probably have to move out for some months - so you would need a hotel initially and then rental accomodation - could you afford several months of whatever is normal for a rented, furnished house in your area?
Could you afford all of that, out of your savings/investments/whatever? I know we couldn't - even though dh is on a very good salary - and that is why we have adequate household contents insurance.
And even if you can, why would you want to spend all that money replacing stuff, when it could be the insurance company's money you are spending?