Yes, but that's only because 2007's iPhones literally had the processing power of 2002's computers, and they were pretty slow at running a stripped down OS X. Not to mention that OS X got significantly faster between 2002 and 2007. On the same hardware, 10.5 (what the iPhone's OS is a branch of) would be a good bit faster than the version 10.1 that was available when Gruber wrote his article.
And let's not forget that the article was written back in the days before flash-based iPods, so the only way to get storage on it was via hard-drive. I mean, we're talking back in the day before iPods had USB connectors, and 2 years before the iPod Photo