Just nope. No "Ummm..." about it. That's bad product design.
The engineers who didn't take real users into account when they designed the product.
As a product designer, if we see a situation where users are confused, or often make the wrong choice, we absolutely regard that as a failure of interface design. We’ve all seen products where simple procedures that should be transparent require consultation with a manual and a series of steps/ button presses that almost no one will remember. Or that act in some arbitrary and inconsistent way. Sure, it may be on page 47 in the manual, but basically it’s bad design and lazy engineering- and it isn’t limited to cheap products.
A big part of why we started making what eventually became the Cobalt computer was watching divers try to do something like set up a nitrox % and being unable to do so without digging out a many page manual. We felt strongly, and still do, that a dive computer’s basic functions should be clear and consistent enough to be understandable without referring to a manual, while on a rocking wet boat.
For us, logical consistency meant that whatever your dive settings were on the last dive (gas, conservatism, or any other parameters), ALL were maintained until you changed them. Change gas = change computer settings. Don’t change gas, the computer won’t change. Consistency is the key to good interface design. Users only need to understand one thing- the computer won’t change unless you tell it to.
As we are surrounded by more and more devices, good & consistent interface design becomes more and more important, and the position that users should just RTFM becomes less defensible. It's easy to not think too hard about the interface, do whatever requires the least effort, and push the responsibility onto the user. From a software engineering standpoint, it’s really hard to make something easy. But good design is what separates great products from everything else.
Ron
