To figure out why this team is struggling to win every day out there, we need to look no further than our lineup. I took a screen shot of the lineup from yahoo and have shown it below.

The Giants took the field today against a less than stellar starter, Ross Ohlendorf. No offense to Ross, but he really is a pitcher that good teams should beat if they want to go anywhere. Looking down the lineup, we can see that most of the Giants enjoyed some success against the pitcher today. 7/9 hitters managed to reach base twice today via walk or a hit. The only two that didn't? Bengie Molina and Aaron Rowand. I know what you're thinking, oh they probably had a bad day or something. (If you're a real Giants fan, you aren't thinking this.) And if it wasn't for a puzzling intentional walk decision from the Pirates manager, Bengie Molina would've never saw the basepaths. He probably walked Molina to clog the basepaths, which is suprising why other managers have taken this approach against him. Which leads me to why they haven't...
Because he sucks. Let's look at Bengie's splits for a second...

Why would anyone have any hope that this guy is a good hitter. He's leaving off where he finished last year. Which is out every single time he gets up to bat. He hadn't taken a walk in 53 ABs until today!
Now, if you want to bench someone you have to have someone to replace him, right? Which is probably what most people are asking, "Who are you going to start instead?" Well if you are a Giants fan, this goes unanswered. If you aren't, but are here because you hate Aaron Rowand, then google Posey, Buster. End of Discussion.
Now the other half of the problem is Aaron Rowand. Yes, he won a gold glove. Yes, he crashes into walls. Yes, he's hitting .220. He's a horrible hitter. Aaron Rowand is the classic case of the player who plays purely because he makes a lot of money. His splits are just as bad and is a black hole offensively. For a team that loses a lot of games by 1-2 runs, this should be addressed... anything to make the team better in the batters box should be looked at extensively. But for some reason, these players continue to play...