Why can I only deactivate an account, and not delete it?

Why can I only deactivate an account, and not delete it?

• Accounts that have transactions posted against them, cannot be deleted. If they do not have a balance though, then they can be deactivated.
• Deactivation is much the same as deletion from the end user’s point of view, the only difference being that deactivated accounts can still be reported on. Deactivated accounts can be reactivated again if necessary.