Your final point makes good sense. However, UK speedway is far from being a great product, it does not use the best ingredients, such as riders, stadiums and universal matchday experience.
If things were done correctly promoters would invest (not divert from current costs)) significant amounts of money on local marketing & PR utilising the appropriate professional agencies whilst the BSPL did likewise on a national basis.
Unfortunately, the majority of the promoters do not have access to the levels of cash or acumen necessary and so sadly they should not be running the sport at the professional level in the UK.
For those folk who currently sit both inside and outside the BSPL with both cash and knowledge of what to do with it to grow UK speedway they will not be doing so whilst the BSPL functions in the significantly less than cohesive manner it currently does - it just does not make good business sense to do so, biding their time does.