But the default serve mux is shared memory (it's literally a mutable global variable in net/http). If it isn't shared memory, what is?
I mean, Go doesn't force you to use shared memory; no language with threads does. It encourages it through library design (e.g. the default serve mux) and language design (e.g. package init() functions) though.
Right, I'm not disagreeing with you that the Go standard library and a few idiomatic Go standard library transactions use shared memory. I'm disputing that these are real impediments to building programs that benefit from shared-nothing designs. Obviously, Go does a better job of minimizing shared memory than eliminating it. I'm asking: does this distinction matter in practice?
There's Go functionality such as pprof that requires the use of the default serve mux and therefore you can't use pprof with a true shared nothing design. The log module is similar.
Does that lead to more bugs in programs? I don't know. It's quite possible it doesn't matter in terms of defect count. It's not shared nothing, though, is all I'm saying.