Yup. Eh, there's the rub. Pianists are notoriously bad at this, and at keeping a beat steady enough the orchestra can follow. (I've never played piano with an orchestra - I have played in an orchestra accompanying a piano)
The problem is that pianists have an orchestra themselves: the piano. The people in the orchestra have to follow the conductor, but the conductor and pianists relation are more like 'playing together'.
I agree, but there's a skill factor involved. The people in the orchestra practice playing with each other and following the conductor every day. The pianist practices playing with the conductor once a year. (slight exaggeration - but sometimes it is never!)
Ofcourse, but i was only pointing out that members of the orchestra usually expect the pianist to be a member of their orchestra and behave like a member, while he actually isnt - and shouldnt.
I usually expect them to be able to count to 4. But...................
My sense of rhythm and exact meter was ruined during years of being a church organist pulling congregations up to speed. These days I switch the metronome on every classical piece I can.
That has been my theory too. You press a key, after a while air fills a pipe, after a bit longer sound fills the church, then finally it echoes back to your ears. The delay is too long for any human nervous system to stay synchronized.