Because you are blaming the victim. The cost of rattlesnake antivenom is not 150k. So being able to charge that means something is broken in the chain of supply.
Just because someone was injured or killed does not mean they are a victim.
Most people have not had any such training with regards to hikes and rattlesnakes.
Everyone is going to have a personal list of "really stupid things" others do. You'll find little consensus on these lists, which means they may not be all that stupid.
You don’t need training to know to not get next to a rattlesnake to take a selfie. They come with their own built in warning—- a loud rattle!