Morinth is like the Jim Jones of Asari. Mixed with Lestat. Like she created death cults that sacrificed children to her and mindrapes people.
Wrex is a just Bounty Hunter, dude.
For fucksake... Can't anyone even have fun with action and sci fi anymore... I never saw people getting hung up about Boba Fett. He was just considered badass. But in Bioware world, everything's always got to be put in some strict moral context.
Oh for goodness sake, take a goddamn chill pill. I already told you I dont have a problem with your favourite bro as well as your waifu. Those are fictional characters in a fictional universe; I couldn't care less if they're space Hitler. I am not condemning them or trying to moralize, I put things into the right context. Contract kills on businessmen on Noveria, Piracy for Saren, trying to kill a friend for money, he was not just a Bounty Hunter dude. He was a killer. If you still want to hang out with him, be my ****** guest. But stop involving me in your pathetic little fandom fights just because I see your favourites in a different light.
Yeah, no. Wrex is a mercenary/bounty hunter who kills on a contract, while Morinth is a mind-raping sex vampire that kills random, unwitting civilians purely for pleasure. You can be certain that she can and most certainly will easily disappear in a place like the Citadel to have her fun with whoever she can lure into her clutches. Wrex presents no such risk, unless I'm suddenly compelled to fear for the lives of crime bosses with bounties on their heads.
Plus, Wrex's presence on the ship does not require us to also betray an ally, whereas getting Morinth aboard requires us to let her kill a justicar, who by all accounts should be the more reliable ally. There's no getting around it: letting Morinth aboard is stupid-evil.
My Shepard chose her solely because of head canon reasons, I chose her because she was a somewhat interesting character who I wanted to explore a little further (and I didn't chose her on every playthrough). I fully acknowledge that in the game there is not one good reason for recruiting her and that the choice, as it stands, really looks stupid. But your implication that you should reject the character solely on moral grounds ... well my take on this is that you can do this in a lot of cases, even though maybe not to that degree. One of those cases would be Wrex IMO, reasons stated above.
Wrex is actually described as being somewhat different from the typical Krogan in Mass Effect 1. It happens with Kaidan at least but I think there are more characters that say the same.
Take Wrex and Kaidan to the Citadel, go to the Krogan statue and talk with Wrex. He will say that the statue represents what the Krogan used to be before they became killers for hire. Kaidan asks "You are not really like other Krogan aren't you Wrex" to which Wrex will say that he will take that as compliment.
Still Wrex will be the first to recognize that he is a Krogan and it's in their nature to fight but he also sees that going down the path of war will be downfall of the Krogan race. That's why he is described as a mutant by Eve.
I'm aware that this is one side of the character, but there is also his other side which you experience for example when you take him to Noveria. I felt like this other side was completely downplayed or ignored in ME3.