Resealable T-Shirt Packaging

This isn't really a dumb thing, just something that my husband brought up as a baffling bit of undergarment marketing, and I can't figure it out either.

Why are the multi-packs of t-shirts and socks you find at most of your big box stores packaged in resealable ziploc bags? If there are three t-shirts in a package, are people likely to take one out and then feel a need to seal up the bag until later? Are lots of people carelessly storing t-shirt packages in an areas where they might get wet?

Seriously, someone explain this? There has to be a reason and I'm just not getting it