In the context of Docker and k8s, Go is the platform language so to speak, and although there are extension points for other languages, one has less integration headaches when using Go as well.
Generics is mainly for users who have committed to Go and new productive language features could possibly help them.
If I'm forced to use a language, it might as well have Generics than not...
It might not be for you, you may rely heavily on Generics in your daily work flow.
If I need generics in my work, I reach for Rust or C++. But when I want to write an easily maintainable microservice that's not trying to reinvent the wheel or need some clever datastructure to handle the work, I reach for Go, since that is what it's good at (at the moment).
The one thing that put me off the most about using C for everything is lack of a common list/vector/map/set standard library for all types. Instead I reinvent the wheel in each project. Go cheats in this regard with compiler magic and that just pisses me off. Atleast you can in theory do printf in iso C.
And a big share of users wishes they add generics - judging from it being the #1 voted feature in the annual Golang polls.
Not to mention the potential users that are put off because it doesn't have Generics...