It (nginx) is bsd licensed. If you don't like the development model, you can always fork it on github, or start a company that develops and supports a closed-source fork.
Not to mention that Cherokee's configuration file format is very human-unfriendly, and its configuration utility is a GUI that requires a web browser (and port forwarding if you want to configure a server remotely, which would typically be the case outside of dev environments).
Let's say Cherokee does not force you to deal with text based, error prone configuration files. Not mention that it allows you to configure your web server safely without the need to learning an additional custom grammar.