I agree, many of the open source licenses are not pairwise-compatible. But the fact that GPL is a strong copyleft license makes collaboration more difficult. 
And the idea that CDDL was made specifically to be incompatible with GPL is at best a speculation. 
See Bryan Cantrill&#x27;s video about the history of Solaris [0] and about different licenses [1]
[0] <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=-zRN7XLCRhc" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=-zRN7XLCRhc</a>
[1] <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=Pm8P4oCIY3g" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=Pm8P4oCIY3g</a>