I'm sure it's getting more and more difficult to find people who can (and are willing to) play an organ well enough to play new-to-them hymns weekly in front of a congregation and not sound like someone's child's recital.

When many small and/or rural congregations are struggling financially just to keep their lights on while also paying for a pastor's salary and upkeep on their parsonage, the decision to allow a RPi MIDI system for a few hundred dollars one-time cost vs a few grand annually for an organist becomes an easier decision.