This is his version of enthusiasm. Steve Jobs wasn't any more "enthusiastic"....he was soft-spoken and straightforward, too, he just didn't stutter/hesitate the way Elon naturally does, so he came across as much smoother.
If you think not having Elon out front and center for this company would be a good thing, you've really not grasped the symbiotic bond between him and his companies and his customers.
This is just another way Tesla is unique-- they don't overmarket everything, they don't run ads, they don't have some slick super-model announce their products. The main engineer, the guy who designed it, talks about it in his own way. I wouldn't have them change a thing.
People like Schiller or Federighi from Apple are both slick presenters, sometimes teetering on the edge of cheesiness, but it's all saved by the fact that you can tell they really know and care about the product.
Whether it's a chosen style or just how he is, to me, it works and feels genuine in a way that's charming. As he talks, I can imagine him sitting down with his engineers saying "Does this = good for the environment, improve safety, reduce car suckage, and is it cool?" And, I can further imagine him digging in to fix it if the product doesn't match, like with diagrams, and left over space x physics books, and a cool napkin he drew on in the shower with a strut design that would be better..
No PR person could ask for more from a lead presenter, seriously. You can imagine him doing that too, I bet, and that's a key and critical part of the tesla brand.
Tesla's launches and reveals are largely Employees + Customers with some press thrown in.