This is weird. Sometimes if you are too polished it becomes boring. I'm not really sure why this is the case. It might be that rather than being polished, the presenter came off as canned. Or maybe the word is trite. In comedy they call it "hack." I saw such a presenter today and it just didn't seem authentic. The jokes fell flat and the audience didn't seem responsive. But maybe I was just being crabby because I had to get up early to go to this presentation.
Lesson for you - don't be the first presenter in a 7 am session. Unless you provide espresso and tons of sugary food items, your attendees might be crabby at that hour and may not be able to pay attention to your presentation. Or might judge your content to be boring.