No, don't fix FTP. At this point it has been rendered obsolete by SFTP which is a subsystem of SSH.
FTPS has lost out to SFTP in the market. There is no advantage to continuing to support a rival and there is a considerable cost. The interests of the community would be best served by focusing all development on SSH/SFTP and declaring Telnet and FTP HISTORIC. Doing that might help focus attention on the fact SFTP doesn't have an RFC and encourage moves to complete that work.
[That said, I am a little peeved at the lack of a telnet system on some platforms as I frequently used it to connect to a raw port and rest out services.]
On the format conversion issue, the FTP spec has a MUST that actually requires the default client behavior to be to assume an ascii conversion is desired.
There being a negligible number of ESCIDC and 9 bit machines on the Internet in the 1990s. this always irritated me to the point of patching the client to remove the stupid.
The biggest mistake in the Web protocols was accepting the dictum of being permissive in what is accepted. Horrors like MIME sniffing might had been avoided if enough browsers had insisted on literal interpretation of content type. What I find really appalling is that there are circumstances in which some browsers have at various times been written with the default behavior of ignoring correctly labelled content and then signalling an error when it doesn't render under the incorrectly assumed type.
