I have witnessed devastating ransomware attacks. When you are working with data and in a world where your infrastructure is the target of organised crime from just about any crevice in the world, liability is absolutely a reason why anyone should consider what services they offer, the impact those services has and if a bad actor was to take over those services, exactly what the impact would be for both the service provider and its end-users.
A backup protects the service providers ability to continue to provide the services, it doesn't really close the loophole that allowed access in the first place. What it doesn't protect is the contact details of each and every person in that list, names, e-mail addresses and a credible source are enough to instigate a phishing campaign from a trusted source and trust me when I say this, people are more than happy to divulge their credentials to a web page they obtained by clicking a link in a trusted e-mail. User-error is partly to blame in most of these cases, but the service-providers reputational damage almost irrecoverable (because blaming the IT guy is always easier).
As for your network contributions... good for you... we wouldn't do things for free unless we felt good about it (no such thing as a selfless act after all)... my comment was specifically around this topic. I think we are all here because we want to contribute something but in the glaring absence of an actual credible, alternative solution to the current problem of a lack of mail-distribution platform and when weighted against some probable outcomes, outsourcing makes sense.