Why inactive members are deleted, while banned members are not.
An 'inactive member' is a member who has not gone on at all, has requested to have their account deleted, or has only gone on once or twice and does not post. These members have not contributed to Societas Magic in any way and so shall be deleted.
Members who have requested to have their accounts deleted will only be deleted if they have not gone on often enough to be considered 'active members'. 'Active members' might be deleted if they have not contributed much to Societas. However, if a staff member or other important member wishes to have their account deleted, their request will unfortunately be denied. We wouldn't want to forget awesome members! So these members will be ranked as 'Honorary Members' and are considered inactive. Inactive members will be informed twice before being deleted. If they come on before the third and final notification, they will not be deleted.
Banned members will not be deleted either. They may have contributed to the forum before they were banned, and even if they haven't, they should not be deleted and set as an example to others. And so we can keep track of their IP address(es) and their behavior, so we can tell whether or not they come back.
So basically, banned members are never deleted. Inactive members are often deleted. An honorary member is a member who is inactive or has requested to have their account deleted but we don't want to forget.