Mac "Pro" is aimed at Professionals, specifically video professionals. It is a logical progression for video professionals who want to move to a newer system with better performance (consideration #1). The "marketing" is not just about better performance but also a smaller, quieter form factor (something Apple excels at). There is no new (buyers) market here, especially at this higher price point. In fact it is even more niche now, with groups like designers and photographers who used to be on Mac Pros can now get much of their work done on the iMacs and MacBook Pros.
I sort of agree with you on this. The Mac Pro of the past, was a designer's dream. it's big and powerful. But, expensive, especially for a poor recent film college grad person in the 2000's finding their way. So, they get an imac. it can do the same thing as the mac pro (especially with firewire). But, slower.
The same is still true today since Apple's price schemes are basically the same for their products.
But, I think the performance gap is not as big. Or, the limit of an iMac is higher to reach than before due to faster tech and better utilization of the gpu within OS X and their apps.
What's different this time, though, is that apple has made the nMP into a "piece of art" because they know that an iMac or a 15" rMBP can do the same thing it can.
They know the Mac Pro is a niche product. So, they made it into a piece of "jewelry," hoping the John Does and Jane Dose will see it and immediately wanna buy it. Just by looking at it. They also know that big design companies value space in their offices and perhaps "mobility" and the new Mac Pro is small and thus easily moved from one place in the office to another.
For the regular consumer, people will see the mac pro as a glorified trash can because they think it's too expensive and wish it was cheaper, more affordable. But, exactly the same. Maybe, have newer gpu's, etc.
The regular consumer is conflicted with the nMP because it is shiny, thus desire-able in their little consumer-y minds. Yet, the parts of it are aimed at a totally different level than them. Economically, financially and practically. They wish they can buy the mac pro to show off to their friends and game on it and use facebook on it. But, you can only do that if you are "privileged." In reality, the nMP is still a workstation, like a Dell, or a Hewlet Packard, but regular consumers are conflicted with it because it is shiny like their iphones and they don't know if they should buy it or better yet, they don't know that they can't have it. the nMP's design is not designed for them.
The way the nMP is designed as an art form is saying you can buy me (if you have $$$) but you shouldn't. Unless you make art on it? And if you make art on a computer, a nMP is art sitting on your desk with you as you make art so it makes sense when the nMP is married in this situation.
But for you and me, the nMP is just that. a piece of art to look at. that you can't probably afford.
and that's ok. buy an imac or mac mini, instead. or a pc or a dell.
who cares in the end?
But beware, I hear they only want to sell them to the pros. 