There is no doubt that as a performance art, a valid Catholic ordination is not a requirement for good preaching or good liturgy. 

The arguments involve beliefs about the divinely established differences between man and woman, the nature of the origin of Holy Orders, and the notion of Christ as the High Priest described in Hebrews of which the earthly priest is the "alter Christus" in the Eucharist's anamnesis of that one perfect Sacrifice.

All three of those beliefs were rejected by the Episcopal Church beginning in the 1970s, by the Lutheran Church of Sweden in the 1960s, and of course by many other Protestant denominations.

Episcopalians who hew to the former beliefs wound up in "continuing churches" or, in rare cases such as the Episcopal Diocese of South Carolina in a diocese which exited the Episcopal Church.

Not all of the Anglican Communion sees eye-to-eye with the Episcopal Church, and as of late 2015 it is under what is effectively a three-year suspension.