I remember when the league tried to get more strict on walking... that was right around the time LeBron and Wade came into the league, and that went out the window. Wade still walks a lot. He'll dribble, pick up his dribble, take two steps, spin move, take another two steps, then go up. LeBron doesn't even seem to care whether he needs to dribble or not. It's basically optional for him.
even non superstars walk a lot in the NBA. Take for example the ty team I follow. Rip Hamilton will come out of a set to the elbow, receive the ball, take three short steps of shuffling his feet, then come to a stop. It's a travel every single time. He never gets called for it.
I just think the NBA really could not care less. Refs will make a meaningless travel call in the middle of the game when it doesn't matter on some scrub player to keep up the facade that they do care. But they don't. It's like the "heel out of bounds on the sideline" call. They don't really care. They just make the call every once in a while to pretend they're really paying attention. Half the time, the guy probably didn't even step on the sideline.