Maxis is definitely not a "good guy".. He blew up the f*ckin' Earth, he may not be as crazy has Richtofen, but he's still crazy. Because of his love for his daughter Samantha, he's somewhat normal compared to Richtofen, but still..
"Then again, perhaps it is the 115 affecting my mind. I can no longer discern." -direct quote from Maxis
And some random guy even predicted Maxis' Betrayal: "You think you're so smart, huh? Haha. You think you can manipulate everyone into doin' what you want, but we know the truth..." (A stumbling over sound is heard.) "Your calculated works...and your sinister agents. You... you mean to destroy this planet and kill us all! Haha! We're not going to help. No way, no how. So yeah, keep talking, no one is going to hear you because we destroyed everything. Everything electronic, starting with...evil...radio...box thing!" (Crashing sound is heard.)
Maxis: "Regretfully, I must inform you that neither the Earth nor its people will survive."