In Liszt's day piano transcriptions brought the larger works to people who could not otherwise attend concerts--much like CDs do today. Thus, they served an important purpose. When I was first studying piano in the 50s and 60s, playing transcriptions was considered anathema. The purists became riled if you even mentioned a transcription. If a pianist played a transcription of a Bach Chaconne, the criticism was that "There are more Bach keyboard pieces than one could hope to play in a lifetime, so why play a violin or cello piece on the piano?" In the 80s people started to lighten up a little.
Several years ago, Earl Wild selected some of Rachmaninoff's Songs and created a a wonderful set of transcriptions from them. Of course, Rachmaninoff himself transcribed a couple, "Daisies" and "Lilacs", (both of which I've played as well as his original accompianments) setting the stage for a broader effort. I have a couple of Wild's transcriptions, "In the Silent Night" and "Floods of Spring". Both are marvelous in capturing Rachmaninoff's idiom, and I plan to learn and play them both when I have the time.