I bet a huge number of the population who has used the FTP client has never used it for HTTP because... using an FTP client for HTTP just doesn't make sense.
The vulnerable ftp we're talking about here is a completely distinct piece of software, which is generally used only when you want to interactively browse a ftp server. But it doesn't seem to be related much to fetch(1). It has obviously common origins with the OpenBSD one, but I can't comment on how vulnerable the OpenBSD version is.
http://cvsweb.openbsd.org/cgi-bin/cvsweb/src/usr.bin/ftp/fet...