Yes, it's a design flaw. It means the dev can make a mistake, forget to check for nil, BAM CRASH!

I even wrote a blog post about this very thing:

https://wakatime.com/blog/48-go-desperately-needs-nil-safe-t...

Nullable types allow devs to write safe functions (functions that don't allow nullable types as input) and spread that safety through the whole codebase. That safety isn't even an option without having nullable types. Nullable types also mean the compiler knows and warns devs if they forgot to check for nil. There's really no reason why Go sholdn't have nullable types.