When the OGL was originally released, I remember an interview (with someone at WotC) where it was said that the d20 OGL had been released so every 3PP product would require to have the PHB, so they would sell more of it eventually. However, with games like C&C, True20, Arcana Unearthed or Conan d20 you really didn't need to buy the D&D books. In fact, at some point I entirely ceased to buy any WotC product, spending all my money on 3PP stuff. So, it's perfectly understandable and normal WotC does a license much more restrictive for 4e. Just I had ceased to buy WotC stuff because they had gone in a direction I didn't like. So, even without the OGL I wouldn't have bought WotC stuff anymore. I would have attempted some other game out there. There are many that seem really interesting, but there is so little time to try them all. In the end it's not OGL/GSL that will do the difference, but products' quality...
And this was somewhat necessary. Keeping in mind that the OGL and D20 licenses were intended to get a "core operating system" for RPGs into widespread use, so the rules could be used for any number of games. Great objective.....but D&D isn't one-size fits all....many settings or games have different underlying assumptions than what you find in the Players Handbook. Could you imagine trying to do Legend of the Five Rings with orcs, elves, and dwarves? Or what about Black Company or Thieves World with paladins, druids, and elven bards? It just wouldn't fit.
Thus the need for books with different assumptions. But I think it worked too well in some cases. It sounds like you were in a similar position as I. WotC, a few years ago (around the time of 3.5) started branching off in a direction I wasn't interested in. I guess, in the absence of an OGL and D20 license, it would have meant that I would have quit playing D&D at all....or at least quit being a customer. But under the D20 and OGL licenses I was able to find companies producing products that still appealed to me. I still did buy WotC books....I was just more picky about which ones I grabbed.
The new GGL seems intended to force the player base to buy and play D&D the way WotC wants it, and seems to be prohibitively against the innovation that arose when all these 3PP companies started producing books.
That in itself is kind of odd, because 4E, as it stands, might not exist if it *weren't* for the OGL and D20 licenses, and all that innovation from 3PP. Guys like Mike Mearls, who was involved in the creation of 4E, got their start in 3PP companies, did they not? This statement does not mean there never would have been a 4E.....just that WotC benefited from getting designers who arose because of the OGL and D20 licenses, and those designers contributed to the direction of 4E.
If I owned a publishing company, I'd be very hesitant about signing the GSL. As a consumer, the GSL sets off alarm bells for me in any case, because it seems intended to prevent companies from innovating and branching off the way they did in 3E......and that branching off is important to me, because *IMO* WotC has gone in the wrong direction with this edition of the game (again, IMO). So in my mind, innovation is what we need more than anything.
I tend to agree with the posters who posit that maybe the GSL was written in a restrictive fashion on purpose, in order to prevent consumers from getting up in arms, but with the intent of saying "hey, we tried, we made the GSL, but they didn't want to sign it". If that theory is correct, in 5E, we might not see a GSL at all.
Banshee