I imagine similar conversations took place in Britain in the 1960's when the first Japanese motorbikes arrived in the UK. At first they just weren't good enough, compared to Nortons and Triumphs. Early adopters were sneered at, the proud riders of Brit iron rumbled and roared into the distance (usually stopping around the corner to fix oiled plugs).
But the Japanese persisted and they got better, bit by bit. More Hondas and Kawasakis appeared and people started to actually enjoy them, their ease of use and their reliability gained supporters. The Brit manufacturers secure in the vocal support of their customers dismissed the upstarts.
As the product developed their handling improved, their performance improved - they were of course always more reliable.
Then another new generation of products arrived and suddenly they were faster, better handling and of course still more reliable and cheaper - much cheaper. Almost overnight the British bike industry disappeared, the manufacturers just couldn't grasp that people are ultimately pragmatic, often conservative but ultimately pragmatic.
Why buy a bike that is slower, doesn't handle or brake as well and is a hassle to own and use when compared to the new stuff and much more expensive? Answer only an idiot or sentimentalist would and there just weren't enough of those about to support an industry.
I own a Canon 60d, I'm pretty happy with it, but I'm thinking of upgrading, so I await the new 7D mk2 with interest. But I wonder how good will it be? How much better for example will it be compared to a Panasonic GH4?
It will definitely be a lot more expensive, the body will likely be 20% heavier and (assuming the 7D is an APSC) all of the lenses will be much larger.
So will the new Canon's feature set and image quality be a sufficient step above the GH4 to justify the cost and weight?
Will I go from my old Triumph to a flash Norton or jump for the Kawasaki?
You could of course just as easily point to many products that were talked up as likely to upset and existing market that roundly failed to do so, indeed Sony themselves have been behind two of the most famous ones in recent decades with Betamax and Minidiscs.
Where this question becomes relevant of course is whether it should inform your buying decisions today. In that reguard I have a lot more confidence that the EOS and F mounts will be well supported in 5 years than I do any current mirror less mount.