what is so sad about that is how the emperor screws them over and how the almighty ultramarines did his dirty work
Would you feel that way if the only thing that changed was the chapter that 'did his dirty work'?
And how did the Emperor screw them over? Before Lorgar was even found or the Space Marines perfected the Emperor said "Religion is bad." And Lorgar went around spouting religious nonsense. He did it to himself, and deserved to get a scolding. Since that's all he really got was a scolding. Kurze got locked up for his misdeed and summoned to face judgement. Lorgar just got told "No, shame on you. Now go about your business."