"cabin attendants are here for your safety" - how do you feel about this?

I travel a lot and while I do that.... I think sometimes. not always, just sometimes. 
anyways, I believe it was on my last trip that I started analyzing the fact that cabin attendants are on the flights for our safety, as we are told. really?? well, I thought about some scenarios where we could potentially need some help from them and see if they could really be our heroes:


 - scenario 1. the plane is hijacked by a terrorist group.
are cabin attendants part of a military trained force we're not aware of? kung fu masters maybe? are they trained to deal with this type of situations? NO


 - scenario 2. somebody is seriously sick on a plane.
how many times have you listened "if there are any doctors on this flight please refer to a cabin attendant". 


 - scenario 3. emergency landing or similar.
this could be a hectic situation and let's be serious, the age of most cabin attendants is quite high... can they physically or mentally deal with a plane full of people suffering from a panic attack? NO


- scenario 4. "turn off all electronic devices"
this is an everyday one...how many people really turn off all electronic devices? I'm pretty sure at least 20% of the people don't. however, if we could have engineers/scientists telling us the consequences of having them on, I think people would follow the rule a little more.
.........


just these few scenarios make me think the statement we all listen to is very wrong or very concerning (depending on how you want to look at things). how can we trust airlines if they are so misleading? 
even if I'm not a fan of cabin attendants behavior, I have nothing against them. just wanted to make a point on something I think is hilarious. any thoughts?