Going by the allegations in the reports, it wasn't just frostbite. Bioware chose to dump a lot of time into features like procedural generation (and having to use Frostbite exhasterbated this problem even more).
The procedural stuff was just a " while we leap of the cliff with no plan" let's make the cost cutters happy who wail because there "abandon working system" for completely different system that's working for a completely different usecase did not work out. Honestly for decisions this clueless and value endangering a whole executive floor should have been let go.