Go onto a site such as Amazon and search for hymns and you'll find plenty of recordings with cathedral and college choirs producing beautifully sung versions of hymns. They are fine to listen to. But we don't do any recordings with singing on.
If you play such a recording through your sound system, the result is something that is harder to sing along to than the accompaniment alone. The perfection of the choir can be off-putting - what we are trying to do is provide the next best thing to having an organist accompanying your own voices.
We could record tracks with a choir: John is the Director of Music of a very fine one at Nottingham Parish Church. But there are plenty of existing recordings, and there is limited scope because it means getting a whole choir together for each track. By limiting our recordings to accompaniments we are able to provide the enormous range of the collection, adapting to different styles and denominations.