Not yet again !

[Brian Goetz]

> You may find easier to answer to a direct question:

Since you're the one complaining, the burden is really on you to explain 
why it is _not_ a good idea.  But I have an answer anyway:

> Why do you want the tearability of a nullable value type, which is an implementation detail, to be part of the type system ?
>

Because it is not an implementation detail.  It is a semantic property 
of the class that describes how instances may react under race.   
Whether or not a marker interface is the best way to do this or not, 
this is 100% fair game for representing in the type system.

Got any other arguments?