Dilandau3000 wrote...
Here's something I've been wondering about: is the quarian immune-system situation in ME2 a retcon?
In ME1, when Shepard first talks to Tali about her suit, she says quarians need suits because they grow up in the sterile environment of the Migrant Fleet. This made sense to me, as even nowadays you see some people with weak immune systems because we've become too obsessed with hygiene and are not exposed to the small quantities of contaminants that build your immune system. As soon as that bubble bursts, these people get sick, and I imagined the quarian situation to be the same.
The problem with that is that it implies that they don't wear the suits on the Migrant Fleet, but in ME2 we see that they do, and we're told that their immune systems were weak anyway. ME2's interpretation seems to be that they had weak immune systems from the start, and it got worse because of their reliance on the environmental suits since they left the homeworld. But that directly contradicts Tali's statement from ME1.
It also never made sense to me that Shepard et al need to wear oxygen masks on the Migrant Fleet. If it was to keep the environment clean it would make sense, but why do they care about that if they wear the suits anyway? And since it doesn't look like the suits have much of an oxygen supply, I assume the air in the fleet is breathable (the suits just filter it). There is also a line from Tali in ME1 about "silence means that an air filter is broken", which corroborates the idea that the Migrant Fleet air should be breathable. Of course, it's conceivable that it's not breathable for humans, but some indication about that would've been nice.
It's not a particularly bad retcon--if it is one--and it won't make me stop liking the game or the quarians, but I'm curious what your opinions about this are. 
It's not implied that they don't wear their suits on the Fleet ships. In fact, you quoted something from ME1 that implies the opposite. Their ships are so patchwork that any moment, they could potentially have a hull breach, air filter gone haywire pumping deadly gas into the living quarters, or any number of reasons why it's a good idea to wear the suit with an internal oxygen supply. Plus, in Mass Effect: Ascension (which came out a year or two before ME2), the quarians were also all normally wearing their suits on the Fleet, for a measure of privacy in the crowded living conditions as well as safety reasons.
The air is breathable on the Migrant Fleet for sure. The point of Shep and co. wearing the facial masks, armor, and whatnot is was to keep foreign matter out of the sterile environment. Unfortunately, modeling limitations made that whole bit kind of ridiculous. Citing Ascension again, some human visitors to the Migrant Fleet were made to wear environmental suits during their stay, to prevent contamination, and I'm quite sure that setup would've been preferable on Tali's loyalty mision for the non-armored quaddies. It was (very unfortunately) no doubt too much to ask the modeling and texturing teams to make new outfits for Miranda, Mordin, Thane, Jack, Jacob, Kasumi, and Zaeed, for a single mission in ME2.
In other words: nah, all this isn't a retcon. More like a clarification. It'd only be a retcon if the two sources of info. didn't jive. Even though some annoying handwaving is required to overlook the ill-suited squaddies on Tali's loyalty mission.