DOS feature on formatting disk

[Dwight K. Elvey]

Hi
 DOS has an irritating feature when asked to format
a disk. If track 0 is partially readable it will
fail to format, even if you use the /u option.
I've been moving data from one machine to another
and the source machine has a flaky drive. It sometimes
trashes track 0.
 I've found that the only way to get around this problem
is to wipe the disk with a strong magnet.
 Why can't it just try to format first and then check
track 0. Why must it fail to format because track 0
is partially readable when I specifically asked it
to unconditionally format?
Dwight