When the time between releases is measured in years you better be sure that new features are somewhat stable before you ship, especially when customers take a long time to upgrade because of the support you offer them. We always have to make a judgement about when things are ready enough but it is much easier now than it was back then. Sometimes we guess wrong but with faster release cycles it is more possible to fix things so we don't have to be _quite_ so conservative. We can also ship things behind flags now (which is how we are experimenting with modules) and we can include things in Insider builds so you can try them without waiting for a full release.