Looks like you are not getting my point, so I looked up an old reply from Adam.
https://community.enhance.com/d/1537-version-1080-is-now-available/46
In this message he states some people are still running older versions. This makes it look like they always have to write a whole new upgrade routine for all older versions. I would think (as a developer myself), the system would use the current upgrade routines available. Because, you know, they are already there. So, let's assume you are still on version 9.10.0, in my mind the upgrade would go as follow:
9.10.0 => 9.10.1 => 9.10.3 => 10.0 => 10.1 => ...etc
now it just looks like they always try to jump to the recent version,
9.10.0 => 12.0.0
An insight in the upgrade process taking place at the moment would be greatly appreciated. π