Look, most of these guys are not public speakers. They are coders or designers or corp execs or mid-spectrum reclusives. So this is not generally their thing and they are trying to muddle through and satisfy their bosses and the stockholders and their moms as best they can.
I get on stage and live tv every day for a living. That doesn't mean I'm perfect at it (as the internet tells me every living minute of every fucking day) but I do love the games and I am genuinely excited to be there. So hopefully that comes across.
I think the other thing is just to lean out and focus on the games. We're all there to get stoked about what's coming. That should always be the focus. I won't knock trailers because I get as excited about them as the next person but actual gameplay, live or footage, is always the best (even if it's curated and managed to within an inch of it's zeroes and ones).