Aperture requests serial number after every reboot due to improper permissions on ProAppsSystemID

Question

Background: if Aperture doesn't have write access to /Library/Application Support/ProApps/ProAppsSystemID then it continually prompts for registration information, and stores it in /tmp/ProAppsSystemID. On restart this tmp file is removed, and thus re-requested every time.
The resolution for this issue is to:
open Aperture and re-enter your registration / serial number (for the last time)
close Aperture
Execute these commands in your terminal:
mv /tmp/ProAppsSystemID ~/Library/Application\ Support/Aperture
sudo rm /Library/Application\ Support/ProApps/ProAppsSystemID
sudo ln -s ~/Library/Application\ Support/Aperture/ProAppsSystemID \
  /Library/Application\ Support/ProApps/ProAppsSystemID
restart Aperture
What we are doing here is replacing the actual license file with a link to the same file where we can write to it.
Question: why is this required? Files like this should be stored in ~/Library/... or created only during registration, with admin prompt, and then read only from then on.

Answer 1

Thanks Leonie,
Your replies on this issue elsewhere lead me to the solution.
The issue is that the *installer* doesn't require write access, but actually Aperture itself, every time it runs. That's crazy given I'm not changing the licence every time. The upgrade to Aperture came via the App Store, so I'm at a loss why it requires these broken unix permissions to run *every* time.
User differs on “Library/Application Support/ProApps”; should be 0; user is 502.
If you use disk utility to repair permissions, it will fix these broken permissions, and again Aperture will prompt you for licence information every time. So Apple needs to fix this, and store the licences where everybody else does in /Library/Preferences and fix their application to use read-only permissions on startup.
This might vary on how the application was installed, maybe the full App Store release doesn't do this any longer.
I don't have a Library/ProApps folder, and I don't run my mac users with Admin permissions by default, it's a classic security risk. I guess this is why you're not seeing this issue.