The main problem seems to be really poor process. They told or were willing for their leads to start building stuff out on their own. The rest of the team were

The main problem seems to be really poor process. They told or were willing for their leads to start building stuff out on their own. The rest of the team were "slacking off because business requirements were in the works". They had no review of what the leads were doing. They did not involve the rest of the team in the design and build of the frameworks. The leads, also in the absence of firm business requirements produced highly abstract systems that could cater to many different requirements. The rest of the team couldn't understand it and it was bug prone (and presumably hard to debug). I assume that these frameworks had to be ready by the time the fabled business requirements were finally produced, so there would be some time pressure to deliver them. I have no idea whether the leads bear much responsibility here from what was written. I do know that the way they write software is very likely to produce this kind of result.