No, really, everything Suzaku has done has either contradicted his morals, caused people pain and suffering, or made Lelouch less likely to achieve his goal peacefully.
Suzaku doesn't want to hurt people?
If he joined Lelouch from the begining he wouldn't have to hurt nearly as many people.
Suzaku's GF died?
If he joined Zero in the first place, she likely wouldn't be in the same situation.
Suzaku thinks Lelouch is "wrong" and "hurting people"?
If he helped them from the get-go, things would be over by now. Instead, a greater war is inevitable, more people died in the process of reaching said war, and racism is at an all-time highon both sides.
Really, the faggot should have apologised a LOOOOONG time ago.