The lands in question will be better-managed by the State Parks than the BLM--and safer from encroachment by development. Obstinate freeloaders, however, will have to move down the road a bit.
The state parks are in the business of preserving parkland, and camping. The BLM and similar agencies do not have camping or preservation as their primary mandate. In an era of shrinking budgets, when a parcel becomes too difficult to manage cheaply, the cheapest solution is to close off access.
When RVers whose main goal is camping tell an agency that they don't want an area declared a campground, they're telling that agency that there's no dealing with them. Every agency has disparate groups clamoring for for special treatment--this is no time to send RVers to the back of the line.