Then again maybe I'm a bit psycho-rigid on build management :)
This tends to happen especially in shops that migrate off process-heavy monsters like clearcase and MKS. These tools do a lot more than just version control, and no open source version control system by itself matches what users of these systems expect. You have to throw at least an issue tracker and a good build tool into the mix as well.
Because of "we'll just add a submodule and we don't need a build system and it's only a single one and we'll replace that with a proper build tooling as soon as we have time". And then it's only a second one and suddenly submodules pop up like mushrooms after a light summer rain. It requires planning and forethought, just like a lot of things that should be an obvious huge benefit, but planning and forethought are in short supply in this industry.