A PhD is a very poor qualification for a referee. A PhD is invested heavily in his own thesis and view of his specialty. He will not be fair to other views, almost by definition. His whole training and inclination and habit argues against it. A Masters' degree normally means someone spends their time having to sort through lots of PhD opinions, so that may be more relevant. There should probably be no preference for one graduate degree level over another in resolving these disputes.
Also, a lot of people with only Bachelors' degrees do a far better job of sorting through graduate and thesis opinions. If you look at the background of many people who have run very successful industrial research labs, you'll find that a surprising number of them had no graduate degree at all, or a graduate degree in a field far from the one where they were really refereeing and guiding research and research funding.
Also where there are stark contrasting views of a field, some cognizance of who is in which WikiParty, faction, or has a particular tendency may need to be explicit. You can't have all the trusted parties adjudicating in say physics believing in the en:fecund universes theory, or everyone talking about en:molecular engineering believing in the inevitability of the en:molecular assembler. There are en:mind-set differences here. See twelve levers and systemic bias also on this.
As an example, would you expect to easily find someone arguing "free content is bad" or "the Internet does more harm than good" or "intellectual property law is not strong enough" or "the Western world is evil" among Wikipedia contributors or editors? But yet, you would have to admit, those views need consideration.
moved from 
I think this [the debate over NPOV in the en:Mother Teresa article] displays quite eloquently (no pun intended) the need for a filter project. The current Mother Theresa article is an enormous improvement on the embarrassment it was for a long period of time, but now here we go again. I could list a number of others in this category. Despite this, Wikipedia has a good audience, role, function etc.. It's very worth doing as is. But there's an opportunity to be much more, whether by an approval mechanism, Wikipedia 1.0, or whatever.
If we do the filter project correctly, it will in the medium term vastly improve the "base" Wikipedia too, by concentrating attention on the (many) articles that really need attention. Andrewa 20:53, 21 Dec 2003 (UTC)