The problem is that the terms of use can change at any time. If I'm choosing infrastructure for my business, for example, I can't be sure I've got a handle on c

The problem is that the terms of use can change at any time. If I'm choosing infrastructure for my business, for example, I can't be sure I've got a handle on costs if I'm dependent on the availability of a bunch of SaaS services that can change their terms or go out of business at any time. If I use locally-controlled software instead, I can be assured that it will keep running as long as my server keeps running. The goal is to avoid points of failure that can bring your whole infrastructure down.