Two major things wrong with the Paul George example.
1. George was picked #10, a lottery pick. By definition if you advocate making the playoffs, we won't even sniff a #10 pick. We will be picking late teens to early 20's.
2. How many #10 picks end up being superstars on contending teams? Not many, regardless of the "winning culture" of the team.
It's the players and coach that make a winning culture, not the GM. It's the job of the GM to get great players and coaches, any way he can. Telling his team of mediocre players to aim for the playoffs and then closing his eyes and hoping his draft picks from the 17-20 range become the next Pierce or Paul George is the quickest way to long term mediocrity. Tyler Hansborough was drafted #13 by the Pacers. Why didn't the winning culture make him a star?
Sooner or later you have to sign those players to long term deals or they walk. Would you sign Olynyk or Bradley to a max deal if they stay about where they are but the team makes the 1st round? That would be like the Rick Fox and Dee Brown signing we made in the dark era.
If a player actually becomes a star, like Kevin Love, or even Lebron, they need more than a taste of the playoffs and a positive culture to sign with you long term. Lebron went to the [dang] finals and still bolted Cleveland. Shaq went to the playoffs in Orlando and still left for LA. Same for Dwight Howard.
Instead of hoping your mid-late draft picks become stars, and then decide to sign extensions with you, it's much more productive to acquire assets like AInge has done, and then trade them for proven stars to build a legit contender. Either that, or get lucky by landing a Duncan or Lebron in the lottery, but even then you have to get the stars around them to make them stay.