Thanks everybody for your comments.
I am sorry, but I didn't realize this was a problem at all!
I have also received some nasty comments beacause of this from some members, and to you I just want to say that all the efforts I put into this forum are to improve it for our members. Please understand, I am not moving threads around just to annoy you.
When I set up this site a few years ago I spent a lot of time trying to find the best way to split up the topics on different boards. I was never perfectly satisfied with the set up but I couldn't think of any better way. This has remained since the start and it has been working excellently this far.
If you feel this is a real problem we can of course try to find a solution but am still not yet convinced it is a problem.
One possible option (as comme_le_vent suggests) could be to add a board for discussions about pianists, concerts, recordings etc and leave the Misc. board for anything else. Any ideas for a short and clear name of that board?
On the other hand I am not really happy with some of the discussion about pianists. Sometimes they include harsh personal insults and I think we must show respect for our colleagues and keep these discussions on a professional and constructively analytical level. Many posts and some whole threads have been deleted because of this.
The problem is that nobody answers anything on that board.
The Performance board has 2918 posts so far and Miscellaneous has 2642 so that is not really true. My experience is that interesting topics get replies whichever board they are on.
I must say that I find performances and the act of performing to be so interrelated that it is difficult justify putting a discussion about a performer's performance into something other than the performance board, especially when looking at someone else's performances might be very well instructive to us, in helping our own performances.
I fully agree with you but I think the discussions on ALL of the Piano related boards will help us in our own performances. However, that is not a reason to put everything into the performance board.
The performance board is dedicated to discussions regarding how to prepare and perform at the piano. Most of the threads that have been moved are actually quite far from this topic.
Please keep posting your comments here!

Johan