Sanctuary is a great label because it gives their artists a bit more freedom. It is not about age but just the simple fact that major labels want quick money and follow trends. Once the tide is over for an artist on a major label they are dropped. Major labels often make money-orientated short-sighted decisions and cash in while they can. This is the sad state of the music industry these days. Also most major labels make very short deals (a couple of albums) these days to prevent them being lumbered with an artist with a long agreement in case the artist doesn't sell.
Sanctuary are succesful because they have managed to secure long-term artists (and this doesn't mean aging) with a strong fan base who normally remain loyal to the artist.

Isn't that why it's called "Sanctuary"?