I've seen people that are really good at playing organ play piano really well, but I've yet to come across a pianist that liked the organ. The lack of expression in the keys is what makes the organ a much harder instrument to play in a musically interesting way than the piano, but with the 'schwellwerk' you can offset some of that and you have endless combinations of stops to modify the tone and that's a big part of playing an organ (as well as the footwork).

There are some crazy good organists out there, and they definitely make them come to life in a way that people that don't have the organ as their main instrument would struggle with. I've been to some organ performances that were indeed boring and some that were out of this world, same organ!