What is the reason this is sold as a SaaS instead of a traditional program?

A traditional program would have many advantages for the user:

* No limit on documents per month

* works offline

* Reports (which may contain company secrets) are not uploaded on a third party server

While other SaaS offerings always have some kind if advantage like having integrated support, I'm wondering whether a document converter (this is basically what it is) is the right software for a SaaS.