Why do we need to remember that?

Because matthieuh is an obvious Android fanboy :)

Sorry, did I miss the part where this was just a competition to see who's worse?

That's one way to interpret it, another way is to assume matthieu is indicating to us that these vendor locked distributions are shit, not necessarily one shittier than the other.

Both Android and IOS suffer from these problems that would obviously be toothless if the platforms would just be on github, and the phones could simply be reflashed with custom builds at will.

I can see how that would make it interesting to point out the vulnerability, but I don't see how it works with the "does no one remember?" phrasing.

It was down to an exploit in LibTIFF though, which also effected devices like the PSP and software like Adobe Reader. Apple has done more bizarre things on their devices, like giving root access to the iTunes synching agent in iOS 1.x.