It is correct that pretty much every feature in the Enchantments was named by Peg and Bill Stark and there children during the 40's and 50's. Bill Stark was involved in Sylvester's initial explorations of the area and went on to explore all of both basins in great detail. Bill created a topographical map with the mythological place-names that was sold in Leavenworth alongside the official map until about ten years ago. The Cascade Alpine Guide, volume II by Fred Becky still uses the Stark's names for lakes and features.
I don't recall what the forest service's reasons were for changing the names of some of the lakes. Personally I much prefer, and continue to use, the original names. Of course Peg and Bill were my grandparents so I am probably obligated to have that opinion.
In answer to why they are called the "Enchantments," all of the original non-aboriginal explorers of the area hold to the notion that if you spend much time there you will certainly see magic, an opinion also held by the wilderness ranger who worked there during the 80's and 90's as well as the crew that built the trail up through the Snow Lakes in the 70's (all of whom I know fairly well) I'd say that's been my experience as well.
There is anecdotal evidence that a yearly back-packing trip there supports he health and longevity of a marriage, my grandparents went there every year for over 40 years. I usually make it in for golden week, but I missed it this year due to an injury. I'm planning to ski-through this winter.