It's just my own view that I developed based on everything I've experienced. It can't be boiled down to a single assumption, or a single piece of empirical evidence. I studied economics so I'm very influenced by economic theory. But on the other hand so called "network effects" do imply that suboptimal technologies can become dominant. In practice, I don't think that languages usually become dominant purely by network effects. They need to have a real advantage.
To take a concrete example, Python has very user friendly syntax. This allows people to quickly iterate on code. Another advantage of Python is its complete standard library, and availability of other libraries. But these things probably would not have existed if Python was not such an efficient language to program in.
To take a concrete example, Python has very user friendly syntax. This allows people to quickly iterate on code. Another advantage of Python is its complete standard library, and availability of other libraries. But these things probably would not have existed if Python was not such an efficient language to program in.