I think it's a couple of things.
Firstly, yes, PPC is faster and/or more efficient in certain areas. Boot up time for my iMac under 10.4.11 is only a few seconds off the pace of my wife's MacBook (which is less than six months old). Shut down is about the same speed. Multitasking is a cinch. And updates and software code is far smaller, which does count for something. Every time a software patch comes out for Snow Leopard, it's 300-500Mb in size, and for what exactly? A few bug fixes? That's a massive patch. Contrast this with the 10.4.11 Combo Updater for PPC, which will update the initial 10.4 release of Tiger to the current version, eleven revisions in total, at 186Mb. Yes, we live in the world of broadband, but that doesn't mean we should throw all efficiency to the wind.
I think what Zen.State is trying to demonstrate with his example is that when Apple initially rolled out Intel it was a huge step back in performance on a number of fronts. Those with old software had to upgrade to take advantage of the platform's supposed gains. Saying, "well that's not fair because that software isn't Intel optimized" isn't exactly fair play, as when the Intel Macs first started shipping, there was a year gap between their release and an Intel native Adobe Creative Suite, so this is what prospective buyers were faced with. Snow Leopard is catching up to the performance of the PPC machines in terms of the aforementioned tasks because that's the basis on which the X86 platform works; run inefficient code at blistering speed, and the chips themselves are getting better and better. What Apple had in the PPC, however, was already super-efficient. What they needed instead was just a power boost and a re-engineering (similar to what Intel had to do to the Pentium 4 when it started melting holes in people's computers and they started switching to AMD). The G5 had it's issues, but it could have been replaced with something stellar.
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Secondly, in the earlier part of the decade, Apple was the "Think Different" company. Not the "Throw In The Towel" company. I think Macs lost a lot of soul when they switched to Intel. The designs became more bland, industrial, and simplified, as opposed to shaking things up like, say, the iMac G4, or sticking Blueberry colored panels on what was ostensibly a professional computer workstation (the B&W). They took chances, and now, they look deathly afraid of doing so. None of the designs that Apple has hatched recently, while pretty in their own way, were anything groundbreaking, just an evolution of what was already in place. Likewise, instead of building a PPC processor that could compete step-for-step with the Intel marketplace, Apple decided that it was better to join Intel and provide the ability to run Windows on a Mac for those not entirely sold on OS X.
What seemed so full of promise back in the day has proven to be kind of disappointing. Just my opinion of course.