Hi Sinux,
I think you may be referring to this post, is that correct? There are two options for Project removal. One is Archiving while the other is sending the Project to the Trash.
The Trash option is a little more permanent, in that depending on the size of the Project it may be difficult to revive all the records contained therein. This is why we recommend the Archive approach when a Project is wrapped up and you no longer need to regularly access it. In general we try to be as non-destructive with the data as we can.
Can you tell us a little bit more about your use case so we can better understand the need to completely delete a whole Project?