Why a vernacularization? While a giant of composition, as a librettist, Wagner stunk. The wordiest of wordy birdies, he might use a paragraph to say yes or half a page to say maybe. Then he grossly over spiced his libretti with adjectives, repetitious phrases, arcane words and meaningless blather to fill in the music, making his 'little books' less for poring over, than for snoring over. And that's just the beginning.
Composers set words to music. Wagner set music to his words. And once he began doing that, his working libretto went out the window as he endlessly fiddled with the words to fit his music. Result? The mess described above gets worse.
So, to make these libretti more readable I've: removed countless gratuitous adjectives, and repetitious words and phrases, ditched the 'thee' s and 'thou' s, and repositioned verbs in sentences to conform to our modern common usage. Then there are the gratuitous sentences and even an occasional paragraph inserted for no purpose other than to fill the musical line that often make no sense at all which I've removed for clarity while remembering that they are absolutely necessary in the sung work to maintain the work's continuity.
So now, instead of fighting your way through a text constantly looking up words or asking, "what the hell does that mean?" you have a completely, totally, and deadly accurate text of these operas! Well, sort of ...