I was under the impression that there were legitimate, erosion-based reasons for doing this. Basically, by building a gradual, sloped shore it causes waves to break smaller and over a longer distance, reducing shoreline erosion. Sure they dump the sand in front of the nice houses first because people want it there, but they would still dredge the beaches even if they were abandoned. Or that's the theory at least.

But I only remember reading it somewhere, not where I read it; so I don't know if it's BS pseudoscience. Does anyone who actually knows something about the science behind shoreline erosion have an opinion?

It really depends on the kind of shore, in some places the dredged sand would just be dragged all the way to the seafloor.

IANAMG (I Am Not A Marine Geologist)

I feel like the comment is misleading in so many ways. The first article even has a video showing the 'rich people' filed a lawsuit because they already have a wall protecting them from the 1800's, which is the height of the dune the government is building up. Not to mention the build-up was to protect residents further inland. Beaches are pretty much public property. Private owners have sued to claim newly created beaches up against their properties due to replenishment. I have not read a lawsuit where the government has lost its right to make it public land.