The first is obviously kind of meaningless - presenters aren't standard up and announcing their orientation at the beginning of each session.
But if you actually do watch there are numerous PoC and woman in the sessions.
Is it a flawless representation of the real world? no, while apple may have better stats than other tech companies, that's still a super low bar.
Even once people accept that there is a problem, meaningfully changing the diversity of a large company takes time because you the large existing set of employees will swamp the overall company stats for many years.
I am aware of people and execs who would preferentially choose Ivys and the big private schools, sometimes even specific schools (e.g. Stanford grads). Given the high end schools have also historically been super racist (e.g. explicitly banning black people entirely until that was ruled absolutely illegal), and still maintain that racism after that through a bunch of subtle mechanisms - for a number it's still seemingly deliberate.
It should be fairly clear how in that environment it is necessary to explicitly pay attention to who and how you're hiring in order to avoid simply reinforcing and repeating existing biases.
Developers are not the community. Why is that a hard concept?
Apple is a Bay Area company, based in America. It should statistically show something closer to the actual diversity of the country. Pointing at the developer community as being what companies should be reflective of simply says "maintain the same set of biases".