I agree, we can expect more from the presenters here.
Experts are humans, experts get bored, experts can't necessarily follow your bad presentation.
Underneath it all we're smart monkeys, not robots. You can't force yourself to pay attention indefinitely. It's not in our biology.
No matter how smart you are if you hear hours of presentations in a day, you will only take home a certain maximum amount of the stuff that seemed important.
If you're a presenter, and you have something life-and-death important to say, you should repeat it, you should put it into simple words, you should use appropriate language, voice and maybe even pictures to make it clear.
I agree with your last paragraph but after any bad event you could point at the presenter and say "I didn't consume the information they were providing - therefore blame them not me"
You say we can't absolve the experts from responsibility here, but it appears you want to absolve the presenters of any kind of responsibility.
Why do these experts need superhuman focus abilities while the presenters needn't even have the presentation skills of 8th graders?
But in the end we should maybe change the format of conveying information completely, whoever is to blame here.