Because they don't have seawalls, geotubes, and houses built on their dunes?
That's not the reason they don't consider state parks critically eroded, in my opinion. The county gains NOTHING by nourishing the state park beaches as they already are owned by the State of Florida and available to the public. They could care less if the beach recedes at those locations.
But let's assume that your comment is the case. The "seawalls, geotubes and houses" belong to the beachfront private property owners. Wouldn't it be up to those people to decide if they feel the need for extra protection and then want the government to modify their property via nourishment? Why should the government care if the private property owner does not?
To debate this topic would be ingenuous as we all know the ONLY reason the county wants to nourish the beach is to gain control of the added beach and make it public. And the private property owners do not want to lose their existing control and rights of the beach, ESPECIALLY where it meets the water for obvious reasons.
Everyone wants a front row seat at the water when comes to chair placement.
The county DESPERATELY needs more public beach.
Perhaps the legal conditions of beach nourishment could be modified a bit somewhere along the lines that the upland property owner maintain some kind of control / exclusivity near the water's edge, say 25 feet, again for the "front row seat" aspect, similar to the CU settlement on certain parcels. But the public would have access to the rest of the beach,
INCLUDING north of the ECL (the existing part of the sandy beach before nourishment). That's quite a bit of beach.
And if the beach were to erode to the ECL, the county would have to re-nourish the beach to maintain the public's access, exactly as it is now with nourished beaches.
I believe that could be a happy median from the public's viewpoint compared to no access at all. And it would be more palatable for the beach front owner.
IMO, because CU left such a bad taste in their mouths, BFOs will fight beach nourishment with everything they've got unless a concession similar to the above is made - OR until we are directly hit with a major hurricane and the beach is truly wiped out, not just deemed "critically eroded".