Any serious approach to security begins with a reasonable and clearly defined threat model, and my threat model for my home network doesn't currently include a team of superheros targeting my file backups in an effort to save the world. But I'll definitely keep your advice in mind when I do decide to start executing on my evil plots.

For now my threat model consists of script kiddies and abusive corporations. Self-hosting gets me away from the corporations and keeping my stuff off of the public internet keeps me away from script kiddies.