Should Duncan go out on top?

During the NBA Finals, Rey Moralde of The No Look Pass will be contributing to Project Spurs during the San Antonio Spurs' chase for title number five.
We have seen this before in San Antonio. David Robinson did this in 2003. But would Spurs fans be surprised if Tim Duncan did the same as Robinson if the Spurs win title No. 5?
I'm talking about going out on top.
Tim Duncan is 37 years old but he still seems very healthy at this stage of his career. But if the Spurs win the championship, would you blame Tim for retiring? After all, he's 37 years old and another 82-game grind has got to be taxing for someone who has been in the league since 1997.
Duncan's legacy is secure. If he goes out, he doesn't have much left to prove. He may very well be the greatest player of this generation. If San Antonio gets the chip, that's five championship rings. Maybe his fourth Finals MVP.  Two MVP awards. 10-time All-NBA First Team. Eight-time All-NBA Defensive First Team. 14-time All-Star. 2000 All-Star Game MVP. What else does he have to prove?
If he continues to play (he currently is under contract through next season), then the Spurs will once again be a title contender. Coach Gregg Popovich will manage his minutes expertly once again. And Tim Duncan's fundamental game will hardly diminish. The precise passing. The bank shot that no one else can shoot like him. The moves inside the post. And with Tony Parker having the offensive keys, Duncan can save his energy (as he has in years past) and be a force in the postseason. 
And of course, he'd only add to the legend. He may have a chance for a sixth title. And then he may get another All-NBA First Team selection. Duncan wouldn't mess up his legacy; he'd only be enhancing it.
It's great to go out on top. Michael Jordan did it initially in 1998 (before returning to the Wizards). Robinson did it in 2003. And Duncan can very well do it after this season if the Spurs win it all.
One thing is for sure, I'm not ready for Tim Duncan's fundamentals to go away. I want to see one of the greatest to become even greater. But if he chooses to call it a day, it's hard to blame him. He came into the league and ascended immediately to the top. Then he can exit the league on top. It's only fitting for a guy like Tim Duncan, who is a top guy on and off the court.