I mean, being a smoker and getting cancer isn't really a comparable situation, the smoking may not have even been the cause, and I would always sympathise with someone who had a life-threatening illness.
I'd have sympathy for Gael if she was a new mom who'd had to leave family behind to travel with a partner in the military to some far away place; there's less of a choice, but this is reality TV. Seems like they both lost perspective here.
I'm not criticising you for being sympathetic, it's great that you are, but for me, there's too much selfish choice in this situation for my empathy.