George Karl wasn't really brought in to win a title. You want a title, you don't hire a George Karl (or a Larry Brown). Karl was brought in to bring the Nuggets out of the doldrums there were in at the time. If you remember, they had all these high profile, high salary players, but had this incredibly stagnant offense (Leonard was out for the season and Greg Buckner was their best SG??). For whatever reasons, the coaches at the time couldn't get the offense started. So they brought in Karl.
I'm not fan of Karl (hardly), but I believe he's done was he was hired to do. Get the offense started and find somebody who could hit an outside shot.