A company—a business—is more than simply a collection of its products and its people. To truly be "successful" in a more meaningful and lasting sense, rather than considering just the functionality of things, it is also necessary to consider the values embodied in them. Magic-Flight uses wood not only because it is nearly a perfect fit for the required functionality, but also because it is an expression of our collective values.
If considered *only* from a functional perspective Teflon or silicone could almost work (glass and ceramic are definitely out because of improper thermal characteristics and because they are too heavy). However, both of these products are seriously synthetic and have non-biodegradable lifespans on the order of one hundred thousand years or more. Having a lifetime warranty is one thing; creating yet more trash in the world 300 years from now is another. Wood is truly the best material to use, both from a functional perspective and also from a values and meaning one as well.