All these 4 points are valid and did help golang but I think what took golang to the moon was:
- the immense success of docker based on it which made everyone build their devops tools in go (kubernetes helped too later)
- a very solid and stable http library included in stdlib (plus other networking goodies to easily run your own ssh endpoint in a few lines of code)
tl;dr to get your language some traction, make it solve at least one problem much better than the competition and have someone build a super popular open source project on it.
- the immense success of docker based on it which made everyone build their devops tools in go (kubernetes helped too later)
- a very solid and stable http library included in stdlib (plus other networking goodies to easily run your own ssh endpoint in a few lines of code)
tl;dr to get your language some traction, make it solve at least one problem much better than the competition and have someone build a super popular open source project on it.