Yes, they will probably make more money from OneDrive subscriptions but it will be will help and make things easier for 99% of their users (if not higher).
We have to understand that being on this website alone puts us in a group that is not "normal" (from the content of the site, to the UI, to the rules, etc). I think almost everyone here would agree backups are important but what is the "normal" Windows person supposed to do for that if not OneDrive?
External/NAS is out of reach of most people (to manage if not to buy) and it's local and you really want a cloud backup. And while it would be great if we all had e2e encrypted backups where we had the only key, that is just not going to work for most people. They will lose the key, want features (like search) that don't work unless you pull all the data local, want ease of use moving between multiple devices, or <insert 1000 other reasons>.
Yes, yes, I know _you_ (collective) know how to do that, I get that you can set it up for the friends and family in your life, but most people will not learn or put up with the limitations even if someone else manages it for them.
Honestly, a lot of people (both young and old) have no concept of where they are saving their files, I think saving to the cloud by default is the right call. I wouldn't save a document locally unless I knew one of my many backups would get it safely to the cloud in short order if not immediately. If only to cut down on support calls for myself I think this is a welcome change.
All that's changing here is the default, you can still save locally if you want. It's just another layer of training wheels on technology. As much as that chafes people on this website, myself included often, I think it's 100% the right move. The side-effect of making more money from OneDrive is icing on the cake IMHO, not the cake itself.