This argument could be made for any license that’s similar to another, I don’t think it’s fair reasoning. Why does 2-Clause BSD exist? Why does Apache license exist?
That's a good point, though honestly I never could understand why you would use anything but Apache (for permissive) or (A)GPL (for copyleft). Other options seem like oversights (BSD/MIT don't cover patents) or cutting off your nose to spite your face (WTFPL). I'm sure there's nuance, but I can't seem to see it.
Some prominent former Sun folks have publicly claimed the GPL incompatibility was intentional, other equally prominent folks have disagreed.