I'm not saying Nene is a better player than Parker.... I'm saying his injury impacts the Rockets in a negative way more than Parker's injury negatively impacts the Spurs.
Without Nene, it basically guarantees that Ariza and Harden will be playing defense against Aldridge or Gasol when they are both in the lineup.
Huge advantage to the Spurs.
Parker is on the decline of his career, here was an average game for him this year :
25 minutes
10 points
4/9 field goals
0.4/1.1 3P FG (33%)
1.8 Rebounds
4.5 Assists
1.4 Turnovers
On top of that, he's a liability on defense, especially against the Rockets.
Looking at some stats - Simmons has taken about 10 minutes from Parker, Mills has taken 8. The rest is hard to tell as it's split up. Dejounte Murray stepped into the starting lineup, but he plays almost no important minutes. He plays the first four or 5 minutes, and then intermittently until the game gets out of hand.
Jonathon Simmons the last two games
19 minutes
12 points
4.5/10 field goals
1.5/3.5 3P FG (43%)
5 Rebounds
1 Assist
2.5 Turnovers
Patty Mills last two games
29 minutes
12.5 points
4/10.5 field goals
2/7.5 3P FG (27%)
3.5 Rebounds
3.5 Assists
2 Turnovers
Danny Green has also stepped up in the last two games and shot 50% from 3P, when he shot 30% against the Grizzlies.
Simmons is far more athletic than Parker, and a better defender against the length of the Rockets. I'm sorry, but I don't think it's crazy considering the predicament it puts the Rockets in with their frontcourt and Spurs are covering for Paker pretty easily with their backup PG and a swing player who is playing some ball right now.