You bring up a good point. As engineers, we naturally tend to overestimate the importance of engineering and underestimate the value of things like marketing, good management, and intelligent business deals.
However, there are more sites out there that failed because of bad engineering than you think. For example, Friendster could have been what Facebook is today if they had been able to scale the site properly.
Over-planning and over-architecting are often problems, but I think most organizations tend to under-measure rather than over-measure. If you don't know what "the problem" is, it's lot harder to throw money at it to make it go away. And if you can't tell the good engineers and the good consultants from the bad, then you really are doomed, no matter how much you have in the bank.
It is funny to hear Josh complain about stupid clients. After all, if they were smart, he wouldn't have a job.