There is need in the Church as in the State to sound a call to loyalty. Your Bishops, assembled in triennial session, make an appeal for a loyal recognition of our common obligation to render generous obedience in observing in their integrity the provisions of our enriched Book of Common Prayer. ... Such loyalty does not, of course, preclude as occasions may require, special services as provided for in the rubrics of the Prayer Book or authorized by the Bishops; but it does demand of the authorized Ministers of the Church obedience to the rubrical directions of its authorized book of worship, as at all times binding upon priest and people. These rubrics and the various offices of the Book are the solemn expression of the mind of the Church. ... The liberty of experiemental usage allowed during the period of revision should now cease [Quoted in Sydnor's The Prayer Book Through the Ages, p. 104].
In a time when "rubrical laxity" in all orders of ministry runs rampant, it's hard to even imagine anything like this being written today. Could our bishops today even come close to agreeing that all clergy (including themselves) need to exercise this kind of generous obedience? I doubt it.
Nevertheless, the point that the Prayer Book's rubrics provide "the solemn expression of the mind of the Church" remains valid. And while it may be true that there are times and situations that call for greater flexibility with regard to the rubrics, those are the exceptions that prove the rule.
Generous obedience to Prayer Book rubrics is part of the discipline of our Church, and, as such, is one of the ways that we are "discipled" - shaped and formed - as uniquely Anglican/Episcopal followers of Jesus Christ. The extent to which we are unwilling to submit to the mind of the Church as expressed in our Prayer Book's rubrics is the extent to which we substitute the subjective preferences of private prayer for common prayer. Given the centrality of common prayer to our tradition, laying aside that discipline entails nothing less than the undoing of our core identity and a rejection of our unique approach to Christian discipleship.