That's my point though -- it's not "weak" per se. As I pointed out earlier, it is superior to a 4770 and bulk OEM pricing is not a valid comparison to marked up consumer prices. And these prices are more or less in line with the industry, it's not just Apple. While you are entitled to you spend your money however you please, the Mac Pro is probably not aimed at you in particular. The people who buy the base nMP are those who don't need that much CPU power but want the dual GPU configuration. Those who need more threads buy a better processor.
Workstations have never been a "good value" on a performance to price analysis because a lot of what you pay for isn't in the computer itself; it's intangibles such as build quality, reliability, customer support, and drivers. You're buying a pro computer. You're going to pay the pro price.
I have to ask though. Why do you want such a powerful CPU? Is it because you don't feel you're getting what you pay for in the base model (because as I said, you're never going to get a good value out of a workstation)? If you're getting by fine with an i7 Mac Mini, you probably don't need this kind of CPU power anyway and the base Pro should be way more powerful than your needs. Additionally, the 6-core isn't actually faster per core, it just has two more. If your tasks aren't threaded to use those extra cores, they're useless to you.