[RaleyField]

Thanks for replying, this explains things. I guess I extrapolated from my needs too much, I didn't consider users who do daily 10+ GB compressed backups.

I still wonder if there's an ethical dilemma that lies underneath this - is it fair to prioritize needs of users who use your tool in a different way (for backup jobs) over users that use your tool only occasionally, perhaps not even out of their own initiative (they were sent 7z file from a ostensibly trusted source).