What a shame that even Paul Graham seems to be having his issues with a well-considered use of the word "design".

Degrading "design" to mean nothing but "aesthetics" is a view of the past, that young, savvy companies know well to avoid by integrating design from the very beginning of product planning stages.

(Maybe I'm misinterpreting what PG means. Although why else would he feel the need to use words like "fashion" and "hairstyles from the past" as an analogy?)

I'm especially surprised he uses this example because it doesn't even serve his argument well: The design of a programming language is only marginally related to aesthetics. Why not use an analogy that compares to the more prevalent criteria of a good/bad programming language?

On top of that, he makes an array of mistakes in his car analogy, and his use of "good" and "bad" design.

>The Cadillac was carefully designed to appeal to the average driver. The 911 was designed for performance. Which one is better design?

This is a moot question, since in real markets, the answer to this question depends on who you ask. Of course, the Porsche looks better according to today's standards. It's also better engineered, has better aerodynamics, etc. etc. etc. But the Cadillac was more widely available, had more leg room, more space in the trunk. And it was probably less expensive.
So yeah. Neutrally speaking, both of these cars are designed well according to certain criteria.

>It's easier to tell good design from bad when you're not looking at current fashions.

Considering that the 911 aesthetics have not dramatically changed since then, looking at the image of a 1973 model will automatically feel more current, modern and familiar to the viewer.
And speaking of fashion: The Cadillac's aesthetics have specifically gone out of fashion ever since car styling has evolved in a more sculpted and organic direction. No matter what field, anything that's recently out of fashion will be perceived as especially unpleasant and outdated. So how is it fair to compare one product that features aesthetics that are still largely regarded as fashionable, and one that's very specifically regarded as "yesterday" and unfashionable?

>Good design is timeless

If this statement was true, the whole fashion industry would be producing only bad design every single season.
Timelessness of design is also nothing a designer of a product has any long-term control over. A product might be timeless in its design (=aesthetics? feature set? what does PG actually mean?) at the moment of its conception. But if it unwillingly becomes part of a trend (even if just because other companies imitate it), it won't be regarded as absolutely timeless anymore. It will have become a witness of its time, and the trends of that period.
The first iPod could have been regarded as a timeless design when it was launched. But today, it is an unmistakable part of Apple's white plastic period. It is not timeless anymore.

"Design" stands for the planning/execution of all aspects of a product together. That includes aesthetics, feature set, implementation technologies, price point, launch date, market segment and much more. If PG had looked beyond the rather narrow horizon of aesthetics, he could have actually created an analogy that worked for him. Even if it included cars.