Any license that allows you to release your derived work as a proprietary and closed-source decreases the amount of collaboration because now nobody else can collaborate on your proprietary fork. One of the reasons for, say, IBM not to give part of AIX to FreeBSD, is that they fear, justifiably, HP may take their collaboration and incorporate it into HP-UX, giving it an advantage over IBM's proprietary product. If IBM incorporates some übercool part of AIX into Linux, HP cannot use that to benefit HP-UX. Fear of becoming an organ donor is lessened because the receiver can't run away with your liver.
I see quite the contrary.
Any license that allows you to release your derived work as a proprietary and closed-source decreases the amount of collaboration because now nobody else can collaborate on your proprietary fork. One of the reasons for, say, IBM not to give part of AIX to FreeBSD, is that they fear, justifiably, HP may take their collaboration and incorporate it into HP-UX, giving it an advantage over IBM's proprietary product. If IBM incorporates some übercool part of AIX into Linux, HP cannot use that to benefit HP-UX. Fear of becoming an organ donor is lessened because the receiver can't run away with your liver.