I agree, but suspect most such systems are using licences from other closed-source projects, IP from 3rd party agencies they commissioned, and stuff that may we

I agree, but suspect most such systems are using licences from other closed-source projects, IP from 3rd party agencies they commissioned, and stuff that may well have cross-licencing and other crap going on. I doubt a company like BG would do more than just glue together other people's stuff.