[swatcoder]

It may carry downstream license obligations of its own, that prohibit/complicate public release.

Relatedly, they might be hoping that one of the people looking at it might be willing to buy out or take over contractual responsibility for any components that can't be relicensed to traditional open source. Basically, parading the source around like a debutante because other channels to find buyers haven't panned out.

Or it's just real-world commercial code and is kind of embarassing by the standards of public open source projects.