The reason why Monica was attacked has been well explained here.
Parche is a lunatic and I totally support Monica's decision not to play in Germany again.
Of course, we must not confuse the issue, German people and Steffi Graf are not guilty of this, they have nothing to do with it, it was that lunatic, and the german judicial system.
Moreover I find the German courts even more guilty than Parche, Parche is a psycho, a sick man that shouldn't be allowed to be free, but the german judges? what is their excuse?, they are supposed to be educated, intelligent and protect the people.
Also, after the incident, the organizers went on with the tournament, it was played as if nothing had happened, they should have suspended the tournament immediately, it was like human life meant nothing for the organizers.
The WTA wasn't also very kind on Monica.
And it seems they have learned nothing from it. I was in the Canadian Open last year, I could have taken any weapon with me, I was really close to some of the players, anyone wanting to harm a player could have done it with no problems. Parche isn't the only lunatic out there, Martina had to deal with a stalker, fortunately the stalked apparently only wanted to be near her and not hurt her, but they should take preventive meassures to avoid that risk, not act when the problem happened.