Yes, he could be better, but so could Dr.T, PC, and likely most of the rest of upper management (with the exception of AC...this is one of the oldish videos I could find of him - he's well spoken, confident in public). Of course, there is always AM, who is very polished, but he's busy with other things right now.
These people, it seems, are just not public speakers. People like DeSimone and Dr.T are scientists, geeks if you will, and are prone to shyness in front of crowds. What PC's excuse is I don't know, but he could use some work on his public speaking skills as well.
They really could use someone who is good with crowds, and fully up to speed on POET to speak for them. There is some advantage to having the geeks speak, because they really know what's going on, they just don't verbalize it well. The good speaker would use nice words, but could fail if/when deeply questioned about the intricacies of the technology.
It's a pickle, to be sure, but there aren't many easy solutions for it.