Aura
Explorer
New Coke was a better cola then Coca-Cola Classic. Objectively--the Coca Cola corporation spent millions of dollars doing taste tests establishing that.
I would caution against using the testing to assert objective superiority in this way. The testing Coca-Cola did for the New Coke product (how much they spent doing it is irrelevant) did not establish anything more than preference for a few ounces of the drinks in question. It was known, although apparently not well enough, that this method (sip testing) does not properly assess more extended (and, BTW, typical) use: a full can/bottle, or even long term drinking. Results can, and will, be different. Further, the tests did detect a rather visceral negative reaction to New Coke by some of the drinkers. So much, that these test subjects would apply peer pressure to other members of the test group.
The testing overplayed the positive reaction to New Coke by portraying a sip test as a general preference, and ignored strong dislike for the product in a social situation. When the drink went live in the US, it had initial positive response by large segments of the population (even if they didn't hold up over time), and a strong negative reaction in the minority when further undercut the new product--a eerie reflection of the findings of the test. The live product performed according to the test, but the test never assessed what the Cola Cola company thought it did.
The takeaway from this is objective superiority in taste issues is difficult to assess. This isn't to say your contention about the power of branding is irrelevant--I agree with you on that. I think the New Coke story easily bolsters that argument by illustrating the power of peer pressure. I'd even venture that peer pressure is of even greater significance in a RPG, which must be agreed upon by a group, than soft drinks, which can be individually chosen by members of the group.
As an aside, I'm going to hazard a guess 4e will persist for some quite time because it was so different than either its predecessor or successor. And unlike a soft drink, once you've played a game, you still have the books to play again. You don't run out.