Firstly it would be one man and his dog at development meetings ... and most of them would be parents and family who hadn’t paid to get in.
Blow an engine and where does the money come from to replace it if they were on nominal fees , a crash helmet costs £500 , boots £300/400 that’s before replacing worn parts and bent frames and handle bars , the costs to the rider are quite high to put a bike out on the track.
Also would you do such a dangerous sport for little money ?