One goal of Tokaido is to reduce the external dependencies of the precompiled Ruby.
There are several parts of the Ruby standard library that are normally linked against dylibs in your system. One such example is OpenSSL. To reduce external dependencies and the possibility of future failure (for example, if Apple removes OpenSSL from a future release), we would like to statically link these precompiled parts of the standard library instead of dynamically linking.
Also worth noting: psych depends on libyaml, which doesn't come with OSX to begin with. We do not want to rely upon libyaml existing in the system in order to use the precompiled Ruby, so we statically compile libyaml into psych.
In the output below, you can see that Tokaido compiled Ruby has dependencies only on libSystem and libobjc, which are extremely stable OSX libraries, and not on libruby, libssl or libcrypto. Instead, those libraries are statically compiled into openssl.bundle. This increases the portability of the precompiled Ruby and eliminates a number of possible failure scenarios.
Are the changes which enable this something that can be pushed upstream? MRI is supposed to have a static build option, but in my experience it's not been usable without extension hackery.