Literally every project they were involved in would get slower as people needed to stop everything to deal with them.

This isn't Mythical Man Month stuff either - no matter the size of the new project, adding specific engineers to the project made progress not just halt, but actually go backwards, as all the stuff that worked before was now broken.

EDIT: And yes, bad management was a major issue with the team but some engineers seem to be negative sum, even taking management into account.