I think one of the biggest problems is lazy or incompetent LD's.
When I lived in Montgomery, AL, there were 40-50 teams/league, and played 4 nights/week. About 2 years after I moved, some buddies said the LD started to run the league like crap, teams left, and the league went to crap.
Out here, our old LD didn't give a rats ass about softball, (except he catered to women's league because he thought he was going to get laid, which he didn't), and softball would decline steadily every year. This year, new LD, she has no clue about softball, but she tries, and listens to the players on how to make things better. Hopefully this attitude/new regime will lead to better softball leagues here. Only person I've heard out here saying they won't come back is Trip, which didn't surprise anyone