OK?
Nobody argues otherwise. The question is how important this is for the average PC buyer. Declining sales indicate that it is probably not that big of a deal for most people.
Again, I did not say PCIe is going to go away. I said I expect user-accessible PCIe to gradually disappear over the next five to ten years.
I'd honestly expect the complete opposite. PCIe would likely be replaced by something new before ever seeing user-accessible PCIe disappearing. Out of every feature on a gaming rig, editing rig, grading rig, etc., user-accessible PCIe is probably the most important. It's still one of the biggest downfalls of the nMP. The willingness of gamers to throw money at every new iteration of GPU should be evidence enough of its market duration. It's like the iPhone - no matter how small the changes, a large percentage of the target audience still buys every new iteration. Until that stops, you're not going to see much change in these terms.
For a 5 year timeframe, I'd bet money PCIe goes virtually unchanged. 10 years? Just an educated guess, but it will probably be about as prominent as it is today if nothing new and as easily accessible enters the market.