Extensible by design

Godot is extensible such that any team, for any use case, can make it the tool they need. Plugins, extensions, and engine modifications are a first-class part of the Godot experience.

I think this is a great mindset. If people want to add custom features which are less tested then extensions and plug-ins are an excellent way to do so. Eventually if a feature gets popular enough it could get integratred into the main engine if the demand is there.