In the long term, you are probably quite correct. In the short term though, the sea-walls give an impression of safety and protection, allowing the owners to sell their properties at great profit before the values collapse.

Here in New Zealand, waterfront property owners have been making legal attempts to block authorities from placing warning notices in the Land Information Memorandum (LIM) documents. These LIM documents are examined by lawyers when a property is being purchased, so to have a warning about your property in the LIM can seriously affect the value of your property.