I've investigated a bit further. According to Sysinternals' Process Monitor program, both winscp.exe and Windows' ftp.exe desire Traverse permission when the lcd command is issued. Interestingly, in the case of ftp.exe, an error message lcd-ing is only returned when the session was begun with ftp [host name] at the command prompt. When the session begins with simply ftp and then open [hostname] is issued at the ftp prompt, lcd-ing appears to work; a message is returned to the effect that the lcd command succeeded. Furthermore, Process Monitor indicated that - outside of winscp/ftp.exe, in a cmd.exe environment - a simple cd [path] from a command prompt does not require the Traverse permission.
To sum up, I would guess Traverse is a standard permission requirement for lcd (though I'm not sure why). So I just need to live with this and fix the NTFS permissions!
To sum up, I would guess Traverse is a standard permission requirement for lcd (though I'm not sure why). So I just need to live with this and fix the NTFS permissions!