Interesting lecture, though he doesn't really touch on the improvisational aspects of paraphrase, and it's probably more "In Praise of Liszt" than "In Defence of Transcription".
I simply don't understand the musical snobbery which says a transcription or a paraphrase is a vulgarisation of the original. Usually it's a tribute to the original, and it also enables audiences to hear music at a piano recital which they could not otherwise experience. Suffice it to say, I'd be delighted (if rather nervous) to play an all-transcriptions programme at any famous venue, and to hell with the critics and Urtext. I know from direct experience that audiences enjoy and appreciate such recitals. I'm convinced there is a certain school of musical thought which believes that music is to be venerated, not enjoyed. Why? And why can't both be true? The very best transcriptions and paraphrases are lovingly constructed works of art in their own right.