They can say that the "downtown" Seaside will remain public, but as parking gets even tighter, and beach accesses are cut off, the public will quickly stop shopping in the public stores, and stop dining in the restaurants.
I didn't read the article about the sign wars, but know that Seaside had a run in with the SWFD over the posts in the middle of the roads off of 30A, and the SWFD won that battle. It seems that Seaside didn't want the firetrucks to be able to access the private streets in order for them to put out a fire. They also made Seaside remove the temporary marquees at each of those roads, which stated, "Private, residents only."
Oh, Snap!