HI Rok - as far as conductors go, the first thing to be understood is that this works quite differently nowadays than it did in the past. In the late 19th through say the middle of the 20th century, there were many little orchestras and opera houses all throughout Europe, especially in Italy (opera) and Germany (both). There were many places that conductors could go and sort of apprentice with someone, and learn on the job. This is how all of those famous conductors learned their trade. The last few decades, they just haven't had the opportunities to get that sort of training, with very rare exceptions. Every big orchestra does have an assistant conductor, but they rarely get to actually do much, mostly just kiddie shows. If they are lucky, the music director will work with them quite a bit, and be a good teacher.
They do go to music school, just like instrumentalists, but even there, they rarely get to step in front of the orchestra and actually conduct live musicians. So unlike instrumentalists, they rarely get to actually practice what they do. All they can do is study (often at the keyboard), learn scores, practice beat patterns, etc. Then when they get thrown to the wolves in the real world, they also have to deal with fund raising, etc., things they are not really taught in school. It is no wonder, given all this, that there are not many very good ones. It is a very strange set of skills required, almost none of which are easily taught.
And frankly, it is almost always a drag for the professional orchestra when a young conductor gets on the podium. All of us have much more experience with whatever piece is being played than the conductor does. So not only do they rarely get opportunities, when they do, the attitude of the group is not very good, normally, unless it is an unusually talented individual who is actually pretty good. It is usually very intimidating for them, and most don't handle that well, since they are of course supposed to be the leader.
A very interesting book to read is Norman Lebrecht's The Maestro Myth, by the way. Some very good bios in there of some of the really famous conductors through the years, too.
