I tried half a dozen ways to send this without making it public, but I can't figure out how to do that. There is no "go advanced" button on personal messages to attach it. It started as a rant, but I tried to turn it into a "sticky". If the moderators want to use it, as is, or modified, I offer it as a public service.

 

These are very good points and comments.

One point that can be made is that, although all good designers consider cost and complexity in the design process, it isn't always the top priority. Sometimes performance, size, weight, flexibility or other concerns are more important. This is all well known, but when specifying a design, it is helpful to have general constraints on what is the most important priority. Perhaps cost is so critical for the application that it is worth specifying that as the most important concern, even if other specifications need to be sacrificed. Similarly, sometimes size and weight, which relate to complexity, are so critical that they need to be made the top priority.

But, I do agree that very often the above is not the reason for the explicit request for simplest approach. Often it is a very naive concept that a simple and cheap solution must exist, and this is not always, or even usually, the case.