As I've said before. it's so easy to people to blame the rules (which of course, many do), but there are so many bigger issues to blame.
Sadly, society has changed, and speedway is trying to keep up with the changes. Trouble is, speedway is pretty unique, and not all the changes are beneficial to the sport as a whole. I always preferred team racing, but with the variety of formats, the sport always remained fresh. The main reason it was so good though, was because we enjoyed watching four blokes wrestling their bikes around a speedway track.
The desire to win - plus the fact that competitors are supposedly "entitled" to fame and fortune at something they took up originally for the thrill of it - has had a detrimental effect on so many sports.