With classical music particularly, that in a way is almost more important. The thing about quality is it is subjective and people's tastes are different in so many different parameters and interpretive choices that its useful to have different versions of the same piece as far wide as you can provision.
There are some pieces the artist departs from the letter of the page while still capturing the spirit or vice versa (useful for technically analysing the piece) or by eschewing both and radically reinterpreting the music to the extent its practically a different piece. Quality will never capture the sheer range of artistic and interpretive beauty inherent to any given piece or available through good old stochastic performance.