Herby
How could Blake have known?
In Dean's early years the Kings traded roster players other teams found desirable to acquire picks and prospects. He then replaced those he traded with lesser veteran players in order to get higher draft picks with his own picks. This is what it will take again for the Kings to get back into contention 5-6 years down the road.
The Kings should have been honest with everyone and started over in 2017 when Dean and Sutter were fired and done just what you said, although I think 5-6 is more like 3-4 with how little pro development these kids need these days. So many of these 19 and 20 year old guys are plug and play scoring line players and top 4 d-man.
I feel like the Kings have a small but loyal following that would have understood and accepted that, yeah they would have maybe lost some of the newer fans who hopped on in 2013-2014 but they may lose them anyways as the Kings return to the black hole, especially with the return to relevance of the Lakers. In Chicago both baseball teams have basically done this, and it's worked out well for the Cubs while the White Sox are still in rebuilding mode but loaded with good prospects.