"...it has left me convinced that the vernacular was never the problem--it was how the vernacular was done."
Precisely. I would strongly argue that the vernacular is necessary, with the vernacular being defined as a liturgical language closely related enough to one's own native tongue to be able to be assimilated with little or no formal study by someone who attends the services regularly.
Russian and Serbian peasants with little or no education understood very well what the services were saying, even though they didn't speak in Church Slavonic.
The same was doubtless true of Italian and Spanish peasants vis a vis Latin -- but I daresay much less so for illiterate English or Polish peasants, especially with regard to variable propers.
This is of course of much greater importance in the Orthodox Church, where the full cycle of services tends to be done on a parish level, and where the volume of variable material is huge. These services simply can't be followed with the equivalent of a missal/libretto. One has to be able to understand the language "on the fly."
But one would hope that the Catholic Church will begin to recover its own daily office for parish use... with good liturgical vernaculars, of course... :-)
Yeah, it's not a bad policy. For whatever reason it didn't happen that way in the West, and though we had, for instance, the Gothic Bible of Wulfilas, the liturgy never made the transition. Given the grief Cyril and Methodius got (from Germans no less!), it's probably because language like Gothic/Slavonic etc. carried a cultural stigma that we can't readily understand today. Might have been like translating the liturgy into Brooklynese or something.
Interestingly enough, here in North America from the 1600s on, even in the Latin Church there was an uncharacteristic emphasis on translating parts of the liturgy into local Indian languages. Presumably, the utter cultural foreignness of Latin to the Indians contributed to that.