I never said he was a bad director. I liked SM1 quite a bit. I've never really liked SM2, but I realize that, when you look at it purely as a film, it's very good. I personally have thought that Raimi isn't the right guy for Spider-man since SM2, as you can see from the post in my sig, but that's another topic.
Now, I can understand that Raimi was interested in a forgiveness story, but sometimes you have to make sacrifices. The forgiveness arc with Sandman was bad, because we barely saw the character, and the way it played out was weak. If he really cared about giving us that story, and wanted to do it well, he should have done one of two things.
1.) Cut Sandman and incorporated the forgiveness story into Venom's character.
2.) Cut sandman, created a better backstory for Venom, and saved the Sandman/forgiveness arc for another "possible" film if he comes back.
If he really cared about this theme and wanted to present it to us, he shouldn't have forced it in, because it hurt the idea. The story came off rushed, because it was. I know that, creatively, if I were in his position, I would have rather not done it at all, and saved it on the off chance that I might direct again, then force it into a movie when I know the best I could get out of it was a half finished product.
And really, he could have easily incorporated Sandman's story into Venom, and made Venom a more interesting character. Make Venom a divored dad with a sick daughter who works at the Bugle. You could have him be on okay terms with Peter, kind of friendly, but have Brock still be a bit of a jerk, so not too many people are fond of it. Brock's down on money because of gambling deubts, and he can't get his daughter hospital treatment because of it. He doctors some photos of Spidey to get some money, Pete (under the influence of the black suit) finds out and has him fired.
Brock's daughter ends up getting worse and Brock gets beat to a pulp by his deubt collectors. Then Brock gets the symbiote and becomes Venom. At the end with the climatic battle, you could have the original Sandman ending where the wife goes up with her kid and get's Brock to stop. Heck, if you want to push the emotional buttons even farther, you could have Brock sacrifice himself because he knows he can't beat the symbiote.
Right there you get the forgiveness theme, make Brock a more interesting character, and don't have to change established history in comics to do it.
Going back to the original topic though, all I was saying is that, yes, while Arad shares some of the blame for SM3, Raimi definitely has it on his head too.