First it i not a good idea to start a new thread to respond to someone who has answered your original thread. It's confusing and clutters up the list.
Second we're all just users here like yourself, not Apple employees, so no one can answer why something is done as it is done. We can only help resolve problems you might be having with the software.
If you have a suggestion or think you have found a bug you need to contact Apple. Use Aperture->Provide Aperture Feedback