Ragabul the Ontarah wrote...
I just never see a moment in ME1 where Wrex softens in his opinion of Garrus and seeing as he doesn't know "Archangel" Garrus I don't see why his opinion would have changed in ME2.
Granted, Garrus was a bit of a cocky smartass in ME1. He's very turian-focused, probably because he's green. When asked what he thinks about chasing an evil turian (Saren), he will respond that this will restore the good name of turians. He even makes a slight jab at Kaidan for not liking his powerful L2 implants because of the headaches. Garrus says that "Humanity will be judged by the sacrifices its people are willing to make, Lieutenant. The Turians would have kept the L2 implants." When you're talking to the Terra Firma guy, Garrus brags how even the sick and infirm turians will stand at the front lines in war. It's all turian, turian, turian. I think spending time on the Normandy in ME1, serving with different species, has given him food for thought and reshape his opinion. Like you said, he did this with the quarians. It won't change his mind about the krogan or the genophage, but I think he can appreciate Wrex for what he is. I also don't think Wrex would resent Garrus for simply being a turian, because Garrus was not there when they released the genophage. Garrus is simply defending this because he learned this from his father, history class or whatever shaped him when he was younger. They'll never give eachother a brofist or -hug and grab some drinks together to chat a bit, but if we get them both back in in ME3, they'll get along just fine. Their different opinions might collide at times, but there's not really any clear animosity between them on a personal level. Especially when Wrex meets the new, improved and matured Garrus

.
As for Wrex being dismissive of aliens in general, I don't think that's the case. He says the same line no matter who says what. Garrus mentions adolescence, Miranda calls it puberty. He doesn't care about the name. He only knows Grunt has to do the Rite.
Now, I'm off to survive zerg swarms again.