We have some talented people here - quite a few multi-instrumentalists.
Originally Posted by Swiss Matthias
Just wanted to come in and give an answer, but I think you quite did it unfunkyfooted.
It's about that, the piano to me is a bit like a one-man orchestra. You can play up to 10 notes at a time, a great pianist can make it sound like even more.
The only thing missing is, as you mentioned, you can't really manipulate tone and sound greatly, in fact the sound is always quite the same. Except if you are a Keith Jarrett or a Esbjörn Svensson (RIP) who sometimes plays the strings directly.
I agree, Swiss. Some of the most beautiful passages to my ear have been piano. If I had my time again, that's what I would have played rather than drums.