Your information may be better than mine, Pathfinder may now standalone. My source for Pathfinder pays WotC a percentage of sales was someone who sounded confident on a forum
I'd have to get a copy of the book but I'm almost positive (after researching the SRDs) that the 3.5 SRD creating D&Ds largest competitor was an oops.
I actually read an article once that stated WotC considers SRD a success because it did exactly what it intended to do, expand the tabletop audience. I can’t vouch for the validity of that, but D&D has expanded significantly since than so there might be something to it.