First it is usually hard to to know if an architecture is good or bad and often this is determined by current favourite thinking. Let’s just take integration with has run through a myriad of best practices and will continue to do so. So who is really to say if a message bus with endpoint discovery is better than a bus with sockets or a database publishing and subscription model? There are often certain advantages in each model such as easier transactional integrity or lower cost, but at the end these notions are often down to the individual business case or the risk appetite of the organisation the architect is working in. Especially the risk appetite can often render a really great architecture in one organisation to a terrible in another organisation.
However usually the worst architectures in any given organisations are the ones build on consensus. Usually most people will think that an architecture that everyone can life up to must be a great thing, however this plan has the major flaw that the consensus architecture is also owned by the many as it is made up by the many with no one really taking the leadership. So this is also the reason that common architectural standards across an industry are only really successful if you have strong individuals driving working groups.
You will see this dilemma of the consensus architecture as far back in history as in ancient times where building designed on consensus where never really finished or if they were finished they were not looked after. The same happens to a consensus architecture that usually will be great at the planning and paper phase, but once it gets concrete and changes will need to be done a consensus architecture will just follow the path of least resistance and as such in the best cases end up exactly with what you have started or usually far worse as many decisions are done a favour system and as such it builds on many incompatible components that are then hap hazardous pieced together. This is why any architecture, even a bad own of any architect is always better than any consensus architecture.