You forget the typical Corvette buyer is very different from the other brands. Most Chevy dealers don't even let you test drive the car, even if you pulled up in a car twice the value of the 'Vette. You're overestimating how successful this 'Vette will be with people who have a history of preferring other brands or other sports car segments.
I wasn't trying to say the C8 will be a massive success who have preferred other brands. I clearly stated people who still wanted a Supra would probably still pick up the Supra. Mustang people will probably still pickup the GT500. People have different priorities and different reasons why they personally connect with those particular vehicles.
I was simply saying right now the hype is high right now. This isn't the first forum that has had people claim other cars in the price range are now dead( bimmerpost is having a similar reaction). But reality will come back eventually. They may just as well have second thoughts. I was in no way trying to say the C8 will be stealing massive sales from Ford, BMW, Porsche, Toyota, etc.
PS: If a Chevy dealer ever denied me a test drive of a Corvette( or any car) even though they know I was a serious customer and not looking for a joyride, they would lose my business. I will never buy a car sight unseen without a test drive.