This argument for moorings vs slips is a matter of personal preference. I don't think anyone is trying to convince others that they should change their preference.
We could change this argument as to who's slip is preferable to another because in fact each marina is very different. Is backing into a four point tie up with a prevailing 15 knot cross wind and two knots of current better than a bow first port side floating dock with fixed fenders?
When I do dock, I "prefer" a port side tie up because I have learned the art of prop walk. So I get less practice backing into that four point tie up. My bad.
As to why a mooring may be preferable in a storm; I can only speak for MY mooring.
The mooring is an 800 lb mushroom set up.
The mooring has been jetted into the bottom.
The bottom chain is US Navy surplus anchor chain from a Destroyer.
The top chain is sized for a much larger boat.
The pennants are over sized.
Depending on the tide, I have at minimum 10 - 1+ scope.
I have 100 feet of swing room.
There are none of the worries of being tied up against a fixed object. The boat swings into the wind and waves as it was designed to.
Most days I raise my main, drop the mooring and off I go, unfurling the jib as I sail through the mooring field. Return, I furl the jib, approach the mooring, head up, grab the pennant and loop it over a bow cleat. I pop open a cold one as I drop the main and cover it up for the night.
Given the proper prevailing winds, I can sail from my mooring to Block Island and anchor or pick up a mooring and never start the engine.
I sleep under a cover when those tied to land need airconditioning. There are no mosquitos. My neighbors are at least 100 ft away.
My way may not be for everyone, but I'll take it any day over a slip.
Disclaimer: My opinion is subject to change.
As to towns closing off their anchorage to offer rented moorings:
Busy transient anchorages are very bad for the sea bed.
Many people don't know how to anchor and it's often a hazard to anchor in a crowded spot.
Mooring fields allow many more boats than anchoring.
In a perfect world, I would prefer towns didn't do this. However, the world is far from perfect.
I have had too many problems anchoring in busy summer spots. I don't sweat the $40 for a mooring. I do sweat the 35 ft Bayliner who just anchored over my rhode with his little baby danforth and 2-1 scope on fishing line.