SpamAssassin is a bit of a special case. Because it has to be integrated
into your email processing chain, it *already* isn't usable immediately
after download: you *already* have to read a bunch of stuff before getting
it working, and by its very nature virtually everyone using it will have
an Internet connection. (I'd hope most people are already running
sa-update, as well, in which case this 'new' requirement isn't going to be
strange to them at all.)