Maybe I have misunderstood sysprep but the generalize option has nothing to do with user profiles.
I have never had a sysprep remove a user account.
Prepares the Windows installation to be imaged. If this option is specified, all unique system information is removed from the Windows installation. The security ID (SID) resets, any system restore points are cleared, and event logs are deleted.
The next time the computer starts, the specialize configuration pass runs. A new security ID (SID) is created, and the clock for Windows activation resets, if the clock has not already been reset three times.
To remove a user account you would need to use the /audit switch. On install screen open the command prompt (shift + f3) and delete them from there then sysprep again.