Personally, that is a total game changer for me. I have an app idea, to build a custom house management app for my wife and I. I really don't care to put it on the app store and I don't want to pay $99 for a two person app. Now I can make an app that only my wife and I will use.
This is the first time you could install apps on your device without paying for a membership. Previously you could design and test through a simulator for free, now he can build and actually use his app without paying extra as he isn't distributing.
I think you two are talking about different things. You could always distribute to OSX devices. However, now is the first time ever when you can run your app on an iOS device without a membership certificate from Apple. This is very good news.
It never was the case that you had to go through the app store to deploy an app for personal use. The only requirement was to have a paid iOS developer membership.