My publisher wants me to send things to them using FTP. I refused. Their IT staff refuses to run an SFTP server (or HTTPS WebDAV, or anything else that is marginally secure) for them. They also block outgoing SSH from the corporate network. I run an SFTP server for drafts of my latest book and my editor has to download them from home and take them in to the network.
Sometimes clueless customers are the problem. Sometimes clueless admins are. If it's clueless customers, then a clueful admin can run SFTP and WebDAV as options for the clueful customers and just warn the clueless customers that using FTP is insecure and that you accept no liability for data theft that results from it. If it's clueless admins, there's not much you can do about it.
Fortunately, clueless admins tend to leave other holes in their security, so you can usually use one of those to sneak a secure channel through...
Each honest calling, each walk of life, has its own elite, its own aristocracy based on excellence of performance. -- James Bryant Conant