There are less things you can do with GPLed software than BSD software. Therefore, when comparing GPL and BSD, GPL is more restrictive. There is no need for the doublespeak of calling it anything else in a comparison.
Tell me, how does "robust" translate to "there are more restrictions on what you can do with this"?
BSDL software is usually far more restricted by the time it reaches end users' hands. I wouldn't take much comfort from being able to say all the proprietary software I subsidized was really somebody else's fault.
"It's complicated", and depends on a lot of factors: sometimes the equilibrium tips one way, and a vendor basically 'cleans up', ala Sun Microsystems and BSD Unix (the free ones took years to catch up). I think that is less likely to happen in this day and age, but it's a fascinating subject worthy of books, not merely a few comments on a thread.