the 8 reasons can be reduced to one
The key reason is that the EA is not scoped properly as the enterprise wide rather than the IT architecture. All other failure reasons derive from this.
EA is reporting into IT rather than high enough in the hierarchy to make an impact.
It is not sponsored by the business but by IT.
It works in an ivory tower with regard to business with little non-IT audience.
It employs an IT architect, who may not have the right range of skills, that is it employs the wrong person.
There are no proper enterprise wide EA approaches. Those that exist are either ontologies (Zachman) or development processes (TOGAF) rather than EA frameworks. Hence many cling to one of them in the hope that the outcome is an EA. It isn't.
The EA team is policing developments in IT, creating perhaps cultural issues, without generating the EA blueprint that would embedd the compliance in processes and make unnecessary the policing. But the team has no other method to get results, except if they invent their own.