Those beliefs were very successful, but like anything else, times change. DL was put in charge of the Kings at a perfect time for him. He inherited a team with some really good young pieces and at heavy play was starting to become the focus after the cap was implemented and highly skilled teams (Anaheim, Detroit, Pittsburgh, even Carolina and Tampa Bay) had recently won cups. The punishing and possession style of play was becoming extremely effective, which suited his player type perfectly.
The cycle is now shifting back to a more skilled game quickly and it's pretty much impossible for any GM to revamp his roster to keep up in such a short period. The only team that has been close to perfectly built lately is Chicago, who plays a possession game that is more based on skill, it's a nice fit for the play the last 7 years or so.
I don't think DL has much of a choice but to stick with his beliefs. Even if he was gung-ho about shifting to a high-skill team, what could he possibly do? Even without some of the crappy contracts, he'd have to replace 80% of the roster to switch styles. I think what DL is doing now is correct. Do your best to retool and set a goal of trying to win in the next 3 seasons. The alternative is to gut the team now, which is going to have to be done in a few years anyways.
There are two main views on this. Some think that DL should throw everything at it for the next few years until the wheels completely fall off and our vets have lost most of their value. Others think that it might be best to sell off our experienced winners while their value is high, and start a rebuild because the odds of winning in the near future are low. I don't think either is right or wrong, but I tend to lean towards the first option because there is no guarantee that a roster with top guys at key positions could be built again.