I've read the article a few times, and I'm still not sure what point the author is trying to make. However, this quote from the article appears to neatly contradict the title (if that faithfully represents his premise):
How do we manage complexity? We use a number of simple design rules.
I can't help but notice that the graph in this article seems to have an obvious equilibrium point. I think it best describes the issue. There is a balance between capability and usability that maximizes desireablity.
And, if you can shift the capability line to the up-left, or the usability line to the up-right, you end up with a more desirable product. It's all about doing more with fewer features.
This article is based on the premise that people correlate the number of features of a product to the simplicity of using the product. This isn't an accurate premise. A better description of the problem would be that features get added to products without much thought for how it integrates with usability. "The Design of Everyday Things" is a good book that addresses where and why design goes wrong. http://amzn.to/17Wew
Simplicity is subjective. Any given interface may feel simple to some users while complex to others. The objective of interface design shouldn't be to make things "simple" for the sake of it. The objective of interface design should be to allow the highest number of users to achieve the goals they have, while keeping in mind how frequently they want to achieve that goal. Iconography, for example, works pretty weel for frequent tasks, but it may fail when the user is only doing a given task once in a blue moon. When in doubt, and in the spirit of pursuing objectiveness, split A/B testing works pretty well.
Simplicity is the goal. This doesn't mean that you lose features, it means that things must be designed. You can have lots of features and lots of simplicity, it just isn't easy.
Actually my phone only has one button and it is still one of the most capable phones ever made. In fact, I'm writing this on my phone with a single button.
Using morse code, perhaps? With only one button, there isn't really any other way to write (I presume that if you were using speech recognition, you would have said "saying" or "speaking," not "writing").
(Yes, I know that you meant you're using a touchscreen on an iPhone, or something similar. I'm trying to be vaguely humorous, and probably failing.)
(The 3GS, according to wikipedia, has 5 physical buttons and then the touchscreen. The iPhone 4, from the pictures I've seen, has at least 4, and the touchscreen. The fact that people entirely forget about them suggests that the design is extremely good, if people are using them without realizing it, or quite bad, if people aren't using them or realizing that they exist. I am inclined to lean towards the former.)
I'm impressed and unimpressed with the iPhone. There are a number of neat things in the touch interfaces. However the lack of menus is very limiting at times. Tertiary functionality is subsequently missing or obscure.
