prosfilaes
Adventurer
Do we get this worked up about Fruity Pebbles? No. And that's all D&D is. It's Fruity Pebbles.
But it's not. I've bought more GURPS 4e then all but maybe a thousand people. Industries that sell to a few thousand people work differently then industries that sell to a few million. It's more like airplanes then cereal; and I bet Boeing, who has built 1,400 747s over the lifetime of the model, has long talks with each customer about what they want to see in their planes.
Not only that, it's different from the other side. A box of cereal is an ephemeral thing; I open it, I eat it, and it's gone. I then go to the store, and I can buy any cereal I want, and it will go well with any milk I buy and the spoons and bowls I already own. RPGs aren't like that; if you're doing more than reading them, all but the shortest adventure will last longer than a box of cereal. Once you've bought ten books at $30 a piece, that's $300 you've invested; if you play PF, you can't buy a 4E book and expect it to work with what you've got, and vice versa, and changing systems implies at least a $40 investment, without figuring in buying new splat books or adventures. It's like gaming systems or OSs, both of which very heated flame wars.
And like gaming systems or OSs, major changes are dangerous for the company. Done right, they can bring in big money; done wrong, you can alienate a lot of your audience. You'll note that most OSs and gaming systems are providing complete compatibility with previous games and programs, something gaming companies can't (and depending on the business model, won't) provide.