It taps into the idea that life is fair and controllable. Neither of which are true.
It falls into the same category of being rude/ callous/ dismissive to people who are unfortuneate to have more than one awful thing happen to them, saying they must love the drama. There is drama, and then there is bereavement, ravaging illness, spiralling into other things like abuse, debt, homelessness, loss of income etc etc.
People cannot cope with multiple tragedies happening, or just one massive one which destroys your support system. And yes, it happens. And no, they don't deserve it, it's not that they weren't smart enough or clever enough or strong enough... It's just that life can be brutal.
My life has been tragedy after tragedy for the last 5 years, wave after wave of wrecking ball style damage, never enough time to heal or reciver or get on top of life again. I've been destroyed by it (although virtually no one in rl choses to see, mostly there's no one there to see), and i am pretty damn tough and resourceful. Although I fight every day, the only reason I'm still here is to give my son his life. The worse thing has been people's reactions to me as I threaten their preconceptions about life.
I empathize alot 
. Thea kind of platitudes can be very upsetting when you're the exception x