The goal wasn't to promote software freedom but to ensure that anyone could simply download the DLLs and use it in their software without needing to sign an NDA, beg for permission or deal with patent bullshit.
The reality is that there is millions of dollars of R&D in the source code for this (primarily through stuff like camera calibration data, but also the maths in n the background) that they don't want ripped off by competitors.