So ALT Linux has got decent build tools but no one even knows
about those, right?  And starting to use those is somewhat tedious
as it requires ALT installation with a specially crafted user account?

live-builder.iso has been useful enough to consider including its
relative into starterkits skipping regular builds for roughly the
same reasons as those for installers: we're better off helping users
to get onto the stable platform bandwagon than having them excited
with Sisyphus just to hit some wall down the road (even if we warn
of these walls well in advance most of the time), and while packages
tend to get into branches via sisyphus repo it's still better to stay
on the safe side with what we make easily available.