It is probably more accurate to claim the GPL was designed to be incompatible with an entire class of licenses that includes the CDDL, and the MPL on which it was based and any future licenses similar to or based on licenses in that class (of which the CDDL was given that it was made after the GPL).
There is no clause in the CDDL that places restrictions on other files in a combined work, but there is one the GPL. There are people out there who dislike the GPL for that, there are some people who explicitly go out of their way to avoid GPL compatibility because of that and I am sure that some of those people existed at Sun, but I really doubt that the design of a license by a huge organization with many people giving input can be simplified to one guy thinking GPL incompatibility is a good feature.
I also think this happened years ago and there really is no point to living in the past. People cannot distribute a vmlinux file with ZFS linked into it (i.e. not a kernel module, but part of the binary itself) because of that, but that does not stop people from distributing it as a kernel module and that is how filesystem code is loaded these days, so it is a non-issue.
There is no clause in the CDDL that places restrictions on other files in a combined work, but there is one the GPL. There are people out there who dislike the GPL for that, there are some people who explicitly go out of their way to avoid GPL compatibility because of that and I am sure that some of those people existed at Sun, but I really doubt that the design of a license by a huge organization with many people giving input can be simplified to one guy thinking GPL incompatibility is a good feature.
I also think this happened years ago and there really is no point to living in the past. People cannot distribute a vmlinux file with ZFS linked into it (i.e. not a kernel module, but part of the binary itself) because of that, but that does not stop people from distributing it as a kernel module and that is how filesystem code is loaded these days, so it is a non-issue.