A swamp near seashore is not going to help to provide water for people or agriculture. The whole seashore is covered with swamps like this that do not have any particularly interesting ecosystems.
But then, Texas politics is Texas politics, so I wouldn't be surprised if there indeed turned out to be significant abuse of protections laws for political gain...
Maintaining some basic protections on remaining wetlands is probably a good idea.
There are many things society can do without. Water is not one of them.