Preach it! One of my colleagues writes all his machine learning code in Matlab. Brilliant person, has done some incredible research, but can do anything with the code because no organization is going to bring Matlab into its clusters and pay for all the licenses needed to run it. So while plenty of presentations and papers have been written of this research, the actual process of letting people use it takes an additional army of Python developers to translate and test every new feature and enhancement.

This is what happens when you build your career around walled garden platforms. Inevitably, you'll reach a dead end. Focus on learning tools that enable you the most. Open source will always win in the end, because it will never come with this very heavy piece of baggage that proprietary tools have. This is why the internet is built on Linux and not Windows.

Unity is the same way. When you build your career on a technology that a single company can strip from you on a whim, that's a big risk. I really hope that Godot and other open source engines take off after this. It will be a painful transition for many developers, but hopefully it's a lesson very well learned.