well that will save me from having to sign up for it to appease the part of my extremely large fan base who also use soundcloud exclusively!
The only way to get these artists off that platform before their stuff goes POOF! is to start linking these articles, followed by your Bandcamp (or whatever less-volatile platform there is) in the description of your works (good practice, don't mass spam peoples inboxes of course). BC might not be as "social" but that's what Twitter etc. are for.