I think it would be unfair to say that blue is a better color than green, or that flat design is better than skeumorphic. And I don’t think we’d appreciate flat design w/o having been through skeumorphic design first (and poor, misguided attempts at that too).
The website craigslist.com is #50 in the world (#10 in the US), and I think most designers will agree that it looks pretty plain. Amazon.com is #11 and sports a pretty chaotic design. So it would seem that a design doesn’t make or break a product; a product that works really well can succeed in spite of not being pretty. I suppose the design just has to be appropriate. I wonder if craigslist would have been where it is today, if Craig Newmark had tried to keep up with the design trends over the years. I think what’s key for craigslist is that the design looks almost bohemian, which may resonate quite well with the self-image of its users.
But craftsmanship is something slightly different. Poor craftsmanship can be a dealbreaker, and I believe it carries bigger weight than aesthetic preferences. Even if craigslist looks rather plain, it does follow some fairly well-established design rules. It would appear that the craftsmanship is good – the designers know what they are doing, and while you may not be particularly attracted to the site (the taste), the design feels deliberate and done with/on purpose.
As an example of the polar opposite, take a look at Yahoo! classified registry. I don’t know what those pages are for, but it seems as if Yahoo! has no taste. They’ve just mashed a bunch of random ingredients into a very tasteless pie. I wonder if they are maintaining it at all – it sure looks like they’ve abandoned it a while ago. I think the Yahoo page is an example of no taste, and bad craftsmanship. The “New” icon seems completely out of place, and it looks pretty bad.
So, I think it’s safe to say that Yahoo! have failed. A poorly designed page, with no meaningful purpose (that I can see). This sort of thing must be avoided at all cost. Yet it seems that a lot of companies end up with something similar to Yahoo!’s abomination. A lot of times, as developers discover a new technique, they can’t wait to use it – somewhere – anywhere. When I was first dabbling in WPF I did a (terrible) mirror floor effect. I immediately popped it in the administrator app. As it was pretty cool, no-one told me to remove it. It still sits there. Inappropriate and annoying to me. And as time passes, my preferences change. I went from skeumorphic to flat, but I never had the time to redo all the assets. As a result, I have a mix of both styles.
So, I understand why design rot happens, and I am pretty sure that I know how to remedy the situation, but I can’t prove that theres a ROI on cleaning it up. People who didn’t buy our product, are not going to complain about the lack of consistency in the design, and people who did, probably don’t care enough to complain. Thus, the problem appears smaller than it might be. Furthermore, a new, overhauled design, may not sit well with our existing customers, and there is clearly a tendency to want to do everything vastly different a second time around (the second system effect).