What's the difference between "///" and "//go:"? The latter is Go's official convention, it's just that unfortunately some of our older mechanisms predate the convention.
But the complaint is about //foobar: and that is just confusing.
the main problem is not technologie but semantic. If you agree with me that the meaning of a comments is communication between humans, than you must also agree - in my opinion - that comments can not be directives to a tool chain.
It is ambiguous. It is error prone. It is easily solved using an other token.
And in the long run it may lead to madness like Java testing and documenting frameworks.
as for technical problems - I think some really bad ones are mentioned in this very discussion!