It isn't about printing unattended, it's a general restriction on using Acrobat on a server. I don't think Adobe care about printing either way.
Obviously only Adobe know the reasons, but I've always assumed it was to stop a company installing Acrobat on a server and sharing its services with lots of staff, rather than buying a copy each.
It's probably just as well, as Acrobat is wildly *technically unsuitable* for this, as an interactive end user tool, and would let you down.