A very interesting story. I completely agree with the following statement:
A CTO should be technology agnostic. This doesn't mean I don't have a preference. It just means that I don't pick up a hammer and view everything as a nail.
A CTO should always strive to have an understanding of different tech stacks, paradigms etc. When it comes to real-world projects, a CTO should carefully evaluate every possible detail and choose the right stack.
IMO, imposing their preferred stack onto every project is the most dangerous thing a CTO can do.