I'm still not sure I agree 100% that it can't get in there over time only due to my experience. Granted, I aged most of my beers in a pretty damp basement. I don;t understand why the case would be that buckets would get it, or beers that lost airlock water, but not those in carboys or secondary carboys with sealed airlocks (besides the obvious fact that it lost co2 blanket). And in the case of buckets I'm talking about those that sat around for weeks after fermentation was over. But even if it can't get in there "per se" I'm pretty sure none of us are following sterile brewing practices, even you, sean.
co2 is the most important part of keeping a beer fresh, any contact with air lessens the amount of time that beer will retain it's freshness, and acetobacter seems to be one of the easiest infection for people to get and it can't grow in a co2 environment. But even if you brew in a sterile environment and have no worries with infection a bucket that sits around for a month after fermentation is finished will be much more likely to suffer the effects of oxidation that one in a sealed carboy or better yet stainless corny.
I just think it's a bad idea all together. Can't help myself from disapproving.