Wanted to let you guys know I had read your responses. Hadn't responded myself because I didn't see a profitable conversation coming forth, but I could be wrong. To each his own, perhaps, but it still seems to me that Gerrel's choice, like Tali's trial, and like what Raan himself did, is seeking a good thing by evil means. Much, perhaps even most, of the evil perpetrated in-game is somebody seeking a "good" thing through evil means; the cost is simply too high.
Raan seeks a good thing (regaining the homeworld), but pursues it in evil ways (cutting corners, endangering the fleet, not following security protocol).
The admirals seek a "good" thing (resolution about the geth situation), but pursue it in evil ways (sacrificing Tali by putting her on trial).
Gerrel seeks a "good" thing (regaining the homeworld) but pursues it in an evil way (endangering his own allies).
The geth seek a good thing (self-preservation), but pursue it in an evil way (allying with the Old Machines).
Cerberus seeks a good thing (human advancement), but pursues it in a hundred evil ways (Sanctuary, wanting the Collector Base, Reaper augmentation).
Renegade Shepard in Bring Down the Sky seeks a good thing (stopping Balak) at an evil cost (killing the hostages).
Saren seeks a good thing (peace with the Reapers) but pursues it in an evil way (compromising with them, killing many innocents).
Javik seeks a good thing (destruction of the Reapers), but pursues it in an evil way (seeing his allies solely as means to an end).
Gavin Archer seeks a good thing (ending the war with the geth), but pursues it in an evil way (sacrificing his brother David).
Miranda admits Cerberus sought a good thing in experimenting on the rachni and Thorians and the Pragia facility (seeking to make troops to save human lives), but they went about it in an evil way (endangering people, using sentient creatures for slaves and kidnapping and torturing children).
The salarian dalatrass seeks a good thing (avoidance of future galactic war with the krogan), but pursues it in an evil way (lying to the rest of the party, sabotaging the cure, and, if necessary, killing Mordin).
Udina seeks a good thing (help for Earth), but pursues it in an evil way (allying with Cerberus and killing the other councilors).
My point is, one's end goal does not make one virtuous; you have to have a virtuous goal that you pursue by virtuous means (don't make me best out Just War Theory).
Not looking to argue (though, of course, you can); looking to explain.
Or maybe I'm sounding like the King of the Boy Scouts.
My favorite insult-compliment of the game.