Security has many different parts and objective, and it depend on the exact use case. If someone is hosting information on a public website they likely do not care about confidentiality, and they can already have a setup for backups. In that case all they might want from a host service is uptime and by using tor they get .

Naturally there are still risk with using a hosting service even when all information is intended to be public. The owner might change the content (integrity of the data), and it might be removed (denial of service), which is trade off for the convenience of not having to host it yourself and the uptime of 24/7 servers.