While raising a number of valid concerns about the external assessment of PhDs in the UK, Chris Hackley seems to take consumer sovereignty beyond its limits (if it is indeed appropriate to education at all).
In effect, he suggests that PhD external examiners should pass the theses submitted because of the fees students have paid, the time they have spent and the effort they have made. Alternatively, externals should withdraw from the process in the hope that even more generous examiners may then be found.
This view seems to be partly based on the assumption that supervisors have deemed their students' "work to be worthy of examination", as Hackley puts it. In my experience of many institutions in the UK, supervisor approval for the submission of a thesis is not a requirement and cannot be assumed. Indeed, with pressure on completion rates, students effectively must submit before (typically) four years, regardless of how their work has progressed.
Nevertheless, this freedom does help to ensure some protection from dependence upon supervisors and their own prejudices and patronage, a freedom that is not always so evident in the European systems that Hackley favours, regardless of their other advantages.
Andrew Sturdy, Bristol