It used to be the norm because releasing and installing stuff was hard and expensive.

I agree we should be focused on the users, but I think the solution there is not to leave them on various outdated software, but to make it so easy for them to be on the new thing that they are happy with frequent updates.

And I feel pretty strongly about this because I've met people whose entire lives are about keeping old, broken stuff limping along so that pathological bureaucracies can never get their acts together. Sure, it's a living, but it's also a colossal waste of human potential.