Comment by ghaff
Publishers in general want books that are 250+ pages. And that's probably too much for a lot of topics.
The one time I went through a publisher I definitely felt I was padding things. The second edition was better. I took out some of the padding and I fleshed out other topics that deserved it. It still barely made it to the 250-ish page point though.
Do you know what the 250 page target is based on? Knowing the underlying assumptions, metrics, KPIs, or whatever, could be helpful.