When will it finally sink in that Ipads and other mobile devices are not magic, and that many of the features that make it look like it's ready to be on par with general-purpose computers are basically just very very very highly optimized code paths and various tricks to make them seem more capable than they are?
It's not that they're not capable of doing what they do very well - I have two, and I love them. But FFS I remember back in... I think 2012 there was this insane belief that pretty soon all computers would be replaced with tablets and other such consumption-focused devices. I remember Google had "Tablet Tuesdays" where they tried to convince employees - professional software engineers - to do all their work on tablets. Needless to say it didn't catch on, at all.
But with every tablet & tablet OS iteration people think that somehow a super-thin device that needs to devote tons of effort towards not overly consuming the battery is going to be their PC replacement - as in, they will no longer own a general computing device, but just a tablet, and it'll do everything a general computer does. Besides Apple not really wanting that anyway - they don't see that as being where the money is - it's fighting an uphill battle against computers that don't need to fit everything - CPU, memory, storage, graphics hardware, and display - in something thinner than a book. The heat dissipation issues alone are a massive impediment.
The reason Apple isn't adding all these bells and whistles is because they can't. The device is not capable, it's limited by its form factor. Take external monitors (showing a separate display) for example - do people have any idea of the power draw for that, to drive both the built-in display and an external display? All told, if you just sit back and look at all the things that are on the wish list in the article - Xcode, full multitasking, external displays, limit of only a single app accessing an external microphone, etc. - it's pretty obvious that all of these things are "expensive" in terms of CPU and power draw, and that's why Apple isn't adding them. Will they someday? Sure, and by then GC devices will have already leapt ahead.