Let me get this straight because I could be misunderstanding your logic:
Apple is at fault for producing a phone that is slightly less bendable than ALL OTHER phones of the SAME size and price...
So I can sue Mercedes because it dents my bumper when I ram another car? It's proof that I'm right because this year Mercedes strengthened their chassis so it is less likely to bend...
I should also be able to sue Crate and Barrel because the glasses I bought break when I sit on them...
Oh wait, maybe this logic is better, I for some reason (I'm an idiot with lots of time on my hands and lots of money) try to bend my Macbook Pro and darn it it bends, I should be upset about that as well...
Here's a solution, don't try to bend the phone, or maybe don't sit on it, and if you do admit it...
P.S. I have thick thighs, All my pants are tight as a result (can't budge my phone tight, yes life sucks for me), I cycle daily with my poor 6 plus stuck in my pants and guess what, no bending. I freaked when I first saw those videos and it's been a year of nothing.