1. download version X of go
2. Unpack to location Y
3. Tell your OS to look at Y
Sure it's not a single command, but it's hardly complicated.
If by UX you mean some kind of install script that handles those things you can always write it yourself.
The idea of everyone repeating themselves over and over again seems to be almost desirable amongst the community. The concept of DRY is essentially dead as far Go is concerned.
Why exactly can the core team not write this tooling? Why should thousands of independent people do it all themselves to varying degrees? It's a laughable situation.