While true, it's also universally true of just about everything. Yes, using resellers/dealers/etc. means that you have to give them a slice of "your" money. It also frees you from having the scale up the infrastructure and employees yourself. Which is why franchise models (either pure or blended) are so popular.
I suspect the more pressing motivation is that Musk wants to have complete freedom to do things his way without filtering by a middleman who would likely be strongly influenced by the way that auto dealers have historically operated.
That said, a couple of points.
1. As another poster noted, the auto dealer "experience" that many of us are familiar with doesn't necessarily reflect the experience one gets with a luxury car brand. Haggling over a Ford Fusion and walking into a $INSERT_LUXURY_BRAND dealership aren't the same thing.
2. I suspect a lot of folks are underestimating the degree to which Tesla will have to provide local services that look a lot like a dealership as it scales up and certainly as it introduces cars at more mainstream price points. For example, you need service centers--as they are building out today.
