Everyone but Wizards thinks PDFs are a good deal? I'm trying to think of a game I own besides Paizo that has PDFs of its books available (either in addition or instead of). I think Shadowrun is the only one. 13th Age doesn't. Numenara/Cypher doesnt. Fantasy Flight's Star Wars certainly doesn't. Very few games I own seem to think PDFs are worth screwing over all the money they put into developing the dead tree versions.
13th age: PDF is $24.95 from Pelgrane's webstore.
Numenara: PDF is $19.95 from Monte Cook's webstore
FFG has noted that they wanted to do PDF, but LFL won't let them do them for SW. They do release them for all their other RPG lines: 40K (DH, RT, DW, BC, OW), End of the World, and several older games are all in PDF. WHFRP3E was also in PDF starting about 3 months after initial release of the box.
Traveller (Mongoose and FFE): PDF and Hardcover for both current editions of Traveller; Mongoose's supplements made available usually in trade (B5), hardcover (A4), and PDF.
Catalyst: Almost everything is available in both print and PDF from point of release. Including their smaller games, like Cosmic Patrol, and their big games (Battletech/Mechwarrior and Shadowrun).
Kenzer & Co: A&8 and Hackmaster 5th are available in PDF and hardcover.
Margaret Weiss Productions: Hardcover and PDF for corebooks, Softcover and PDF for supplements and adventure ominuses; individual adventures PDF only.
SJG: Most of their books now are PDF; only some see actual dead tree. Note that they support 2 RPG lines at present: GURPS and In Nomine.
The one that doesn't do a full core is C&C... their PDF core isn't the full rules. But is it major? not really. Others in that tier:
LotFP: PDF available
I submit that you may not know what you're talking about, and obviously didn't take the time (60 seconds) to websearch for them, because they ARE available. Of the major games out, ONLY D&D and FFG star Wars haven't released PDF.