They say death and taxes are the only inevitables in life and if you have noticed, we talk about only one of the two, taxes. We avoid talking about death in the same way we avoid the bill after a family dinner. We know it is there, and we know we have to address it but no one actually talks about it.
So why don't we? For some, it's a comfort; for others, it's a curse. And unless you're Voldemort himself, this aversion to your death will not result in dramatic situations. It'd simply be the 800-pound angry silverback gorilla in the peripheral of your mind. Perfectly subtle, easily ignorable.
Without angering this very nice gorilla, let's figure out why we actually cannot say the D word in polite company.