Yeah, put another tick in the "it's best not to over-think this one" column.
On the one hand, the offered explanation(s) don't make very much biological sense ... allergic reactions, compromised immune system from living in a 'clean' environment (but still one that travels all over the place as space-gypsies), a home planet that's completely lacking in hostile or at least predatory microbial life, the fact that the story changed between the two games (now Quarians have to wear their suits all the time on their own, clean ships? Bwuh?), etc.
On the other hand, alien. Who's to say it couldn't work like that? I guess?
The best thing is to just ignore the whole situation and move on.
On the one hand, the offered explanation(s) don't make very much biological sense ... allergic reactions, compromised immune system from living in a 'clean' environment (but still one that travels all over the place as space-gypsies), a home planet that's completely lacking in hostile or at least predatory microbial life, the fact that the story changed between the two games (now Quarians have to wear their suits all the time on their own, clean ships? Bwuh?), etc.
On the other hand, alien. Who's to say it couldn't work like that? I guess?
The best thing is to just ignore the whole situation and move on.