Hello,
I may be wrong but I think Debian:
- develops its own Debian Installer for installation, traditional way
- has adopted Calamares for installation, the way Ubuntu has initiated
it in the past. That is: non bothering non-technical users with setup
questions they don't understand and basically copying a
live-distribution to a hard disk, with a pre-determined setup, without fuss.
So I would say that if a user finds that Calmares is not satisfying
their needs, they would rather use the traditional Debian Installer
instead. I think nowadays (it's a welcome addition), it's also included
in the live Debian distributions...
