No, you're still missing the point. For the sake of argument, we'll assume that using the
CDDLed dtrace code in Linux is a violation of the GPL. Let's also assume that none of the
Linux copyright holders are going to sue anyone who distributes this infringing combined work.
Now let's imagine that Microsoft buy a small Linux contracting company that holds the
copyright for part of the Linux kernel. Microsoft now get to enforce the GPL against anyone
shipping Linux in a way that violates it, and so file takedown notices against Red Hat and
Novell. The only defence these companies would have is "It's not a derivative work of the
kernel", which runs counter to arguments that they've made in the past. Do you really think
anyone wants to be open to that situation?
 As Bryan points out, this is a grey area. But I don't see any of the major Linux vendors
being keen on being the first to have that tested in court.