The number of binaries isn't relevant. Claiming that systemd follows the unix philosophies[1] because it has "many binaries" suggests you don't understand that philosophy.
The point is limiting complexity. Smaller, self-contained programs are a lot easier to understand and debug than both a single "kitchen sink" app and a collection of tightly coupled programs and libraries.
If systemd followed the unix philosophy, I should be able to use journald in isolation. Or I should be able to use the init tools just as without bringing in the other tools. The point of a modular design is that each module should be as independent as possible so they can be replaced piecemeal and tested/debugged in isolation.
It doesn't matter if you split the project up into different binaries/etc. Busybox, for example, shoves everything into the same binary, but it's a modular design where it's easy to leave out any module and use the coreutils version instead.
[1] http://www.catb.org/esr/writings/taoup/html/ch01s06.html