Yet not a single PC manufacturer ever released a competitive machine at a lower price.
Depends on how you define competitive.
For anyone who just wants a cheap desktop machine and doesn't care about size (for whom any reasonable non-huge desktop is competitive), the mini is horribly uncompetitive.
The problem with the box is that it puts all the expense into the feature that most people don't want, at the expense of the features most people do want.
Most people just want a box that's cheap, reasonably fast, and expandable. The mini fails at all three and instead offers SMALL which the average buyer could care less about.
Sure, if you NEED small, the mini is great. The problem is if you just want a cheap machine for basics and don't care about size, the only machine in that price range is the mini, which forces you to waste money on miniaturization.
Some people hate it when the mini is compared to other desktops that aren't "mini", but since that's the only budget desktop Apple offers, there is no alternative and that comparison must be made.
Every Mini since the Intel transition has allowed at least 2 GB.
And at MOST 2 gig. Along with small hard drives, ancient video chip, and not even the fastest wifi. The mini is the ugly stepchild of the Apple product line.
There will never be a midrange tower. It's just not how they do things.
The same was said about the mini, the air, the iPod, the apple TV, and the iPhone. Just because they've never done it before is no reason they won't do it, they have added at least one brand new product about every year. I don't know when it will happen, but eventually you will be proven wrong.
I expect Apple is aiming for an extremely simple line up:
Consumer Desktop
Professional Desktop
Consumer Portable
Professional Portable
Media Desktop
Media Portable
Consumer Desktop is the iMac.
Except that the iMac isn't really a desktop.