You mean there was a time when FSF didn't launch ideological arguments to demand that people use software from the GNU Project?
I'm not picking a side, just pointing out that this is par for the course. If it isn't GPL, it's evil.
They maintain a very comprehensive and useful listing[1] of 3rd party licenses which goes over their histories, tradeoffs, and whether they're compatible with the GPL.
And that compatibility is treated independently of whether they consider those licenses to be 'Free'.
Of course they'd prefer use of their own licenses, but this self-interest takes a back seat to helping the overall ecosystem.