That's really the only meaningful question here. It doesn't matter if it's quantifiably more likely to bend, what matters is if that results in enough phones getting damaged in normal usage to be an actual issue for people. No one will know that for a while.
Non-ECC memory is more likely to get corrupted than ECC memory, but that doesn't mean that every single person who uses a computing device should be using ECC memory. Just because one thing is quantifiably less robust than something else is meaningless without a concept of "how robust does it need to be?"
Obviously the company thinks the phones have sufficient tolerances. A few people on the Internet have posted firsthand accounts that they think proves that the phones are inadequate. A much larger group of people on the Internet who don't like the company that makes the phones practically salivate over these sorts of events, and have been making sure that absolutely everyone who reads any tech forums is HIGHLY AWARE that this is a very important thing that we should all know and care about very, very deeply. Journalists of course will write about this stuff because many of them interpret their job as writing about whatever people are talking about.
Which brings us to the present, in which the only truth that anyone can point to is: no one actually knows if this is actually a problem or not. The only way to answer that question is to wait and see how many returns there are due to breakage. For people who care about truth, well, that's the truth, boring as it may be. In a few months we'll find out if a big company might make less money because somebody should've used a bigger number on a spreadsheet. Exciting! On the other hand, for people who care about arguing about things on the Internet, well, to hell with them, honestly.
However just playing devil's advocate: 9 returns to Apple (assuming that figure is true) is absolutely trivial relative to the units shipped.
I think it will be interesting to see where we stand in 6 months time. Will we see tons more phones return?