Danzauker said:
Economy says that printing, stocking, advertising, selling ONE product makes for lesser costs than TWO products, so it's more profitable.
It's more profitable IF everybody wants a cheeseburger -- or if you've got a Marxist setup to make sure they get a cheeseburger anyway. Otherwise, "It comes in any color you want, so long as you want black" means losing a sale when someone else offers a real alternative.
Well, people are going to offer Tunnels & Trolls and RuneQuest and Rolemaster anyway. If they followed your logic, Chaosium should not have offered RQ in three versions:
(a) boxed set
(b) soft-bound book
(c) hard-bound book
If the real world followed WotC theory, then perhaps RQ3 should have been a smashing success because it was in so many ways such a break from the first two editions (which had not only won awards but made it the #2 FRPG after AD&D). Or maybe it just wasn't different enough? Avalon Hill designed a RuneQuest: Slayers game that had basically
nothing at all to do with Chaosium's classic -- but when down the tubes and into Hasbro's hands without publishing it.
Chaosium, on the other hand, applied the RQ "Basic Role Playing" rules quite successfully and simultaneously to Stormbringer and ElfQuest (plus Hawkmoon, Ringworld, and Call of Cthulhu). The Worlds of Wonder boxed set offered three slimmed-down games in one: Magic World, Future World and Super World.
Each of those appealed to a slightly different audience as well as to some of the same people. That's how it is
right to this day with TSR's various D&D packages, and with the "retro clones" inspired by them. Variety is the spice, but compatibility is also a feature -- just as it was with Chaosium's line-up.
GDW also succeeded with different packages of Traveller, from the original boxed set to Starter and Deluxe, and on to The Traveller Book.
One size, shape or color does not necessarily fit all, in an RPG line any more than in a line of cars or computers.