There is no doubt in my mind that those who liked that system could have written many paragraphs about how it had developed very logically and sensibly and with the needs of search committees, applicants, and the denomination as a whole, and why it was the best possible system but for reasons I don't know, other than John Weston's passion for congregational autonomy, it was changed.
Now the process is much more open and search committees have much more responsibility to discern for themselves who will best serve them. All information about churches is posted, any minister who wants to apply can apply, and then the vetting begins. Among the consequences that I am aware of; some of our large churches are served by young and new ministers, ministers who would not have seemed to the "powers that be" to have earned the right to apply to a prestigious pulpit. Some of our fastest growing large churches are served by these ministers who otherwise would not have had the opportunity.
As we look again at the ministerial credentialing process, I think we should start, not with how we got to where we are, but with what congregations actually need and expect from beginning ministers, and how we can maximize the openness we espouse for congregations while carefully doing whatever examining and gatekeeping we feel we need as a denomination both for the good of the whole and for the good of individual congregations. As a for instance, I think that search committees are often not able to discern the presence of some kinds of personality problems which can wreak havoc in ministry. Things like psychological testing and in depth reference checking might be best done for search committees at the denominational level. As another for instance, we as a whole denomination have a stake in a ministry which is well-grounded in our history and polity; issues of relatively small import to search committees which have much more local concerns in mind. Therefore a credentialing process which looks at a candidate's knowledge in these two areas is important (though I believe that this should be done mostly through written comps, not through the hit and miss spot checking of factual knowledge in an interview process.)
As we take a hard look at our, lets face it, paternalistic credentialing process, I think we should take a good look at what happened when we did away with our paternalistic search process. We might find some cautionary notes, but mostly, I think, that hard look will give us the courage to imagine change.