Finals MVP is a foolish award because it doesn't take into account the other 3 rounds. It should be playoff MVP and if it were, Duncan would have won hands down.
http://www.basketball-reference.com/teams/SAS/2007.html
Parker was very good, but he was clearly the third best player on that team, in what was the collective peak of the big three.
In '14, he made All-Star largely because as the best team in the league, they had to have a representative and his reputation was at an all time high thanks to career best seasons the previous 2, as well as the notion that it was "his team".
He led in points and assists (antiquated criteria) mostly because he led in mpg and usage rate. Though he further declined in the playoffs, on balance, he was probably the 4th best player on that team.
http://www.basketball-reference.com/teams/SAS/2014.html