Sometimes, musical or stylistic factors dictate a preference of either organ or keyboard rather than both. In laudable ways, this eclecticism has helped to unite what used to be warring factions in many parishes. In addressing any type of challenge, compromise is essential. In the midst of the healthy eclecticism just mentioned, I've noticed a new wave of musical segregation arising, which seems to be based more on performance medium rather than musical style. Although organs, pianos, and synthesizers are often classified together as keyboard instruments, perhaps a different view is in order.
Acoustic pianos are really percussive string instruments.
Electronic keyboards can partake of a number of musical families, especially when one sound is layered over another. Of course, no one musical instrument in intrinsically superior to another. But actual practice seems to reveal that both a sustained sound and a percussive sound are helpful for effective instrumental leadership. This is experienced in contemporary ensembles when a piano is augmented by the sustained strumming of guitars, or an electronic piano is layered with a string sound. Even electronic organ manufacturers these days attempt to add chiff to their products.