i dont get it also. i am with the admins on this. if there is a real problem should take it up with the mods/admins if you no longer wish to visit the site for any other reasons its not too hard not to click. deleting a member would leave gaps in posts and confusion.
Mgamer is right - it's best to contact a staff member if you have a concern. Deleting an account would leave "orphan" posts which are not searchable anymore. We could potentially have hundreds of posts disabled like this. We can usually resolve whatever issue you're having if you contact us.
I would suggest the user go in and change their contact details and personal information to something phony. I would imagine people would ask that their account get deleted so that their personal contact information is no longer housed within the site