I mean, (1) has nothing to do with the Sun examples, it's not something unfortunate about CDDL but unfortunate about the GPL. If one thinks of it in national terms: there is a GPL Nation holding its land against a bunch of proprietary city-states; a huge swath of land is occupied by the neutral space of MIT and BSD, people who have no real national identity and GPL is fine with them, "Can you be press-ganged into our army? Yes? Great!". And then there's these strange lands MPL and CDDL which lie close to GPL; they culturally agree with GPL in many ways; they like copyleft and want their works to remain free... but they intentionally have a separate national identity because of practical and historical reasons (at some point they had trade deals with some proprietary city-states). And it's just unfortunate that the GPL does not allow for any collaboration anymore, because "if you have any national identity, that is against our nation's constitution and we cannot work together with you." Meanwhile all of these little nations can work with each other just fine, can work with the proprietary city-states just fine.

Regarding (2), the history is a bit murky. Danese Cooper wrote the CDDL and has said that GPL incompatibility was intentional; but several others have come forth (both at the talk that he said that, like Phipps, and since then, like Cantrill) to say that it was not a design goal at all, it was in fact a compromise between engineers who wanted an MIT/BSD license and management who wanted a GPL license.

The true story seems to be: Engineers were very firm about "if you force people to jump through the Purity Hoops to install proprietary drivers you are increasing the total quotient of worldsuck for generations to come and frankly, why the hell are we opening this system if we're going to make the world suck more." Meanwhile management was very firm about "we worked so unbelievably hard to open this thing up, we don't want some big player like IBM to just fork off a proprietary version, spend a big budget to become the big player in the Solaris game, and then all of our work open-sourcing this damn thing was for nothing." The CDDL was a clean-up of the Mozilla Public License which sensitively addresses both issues, it deliberately contains a big honking wall which is (and everything inside of it is) copyleft open-source, but the license has no problem being distributed with proprietary add-ons as long as the interfaces they use, baked into the copyleft open-source wall as they are, follow the copyleft open-source license of the wall and everything therein.