You may fill in any epithetical blanks wherever you find them here.
The Takata airbag problem is perhaps as egregious a design blunder as one can imagine. It has cost lives. Still, we are beset with design blunders at many levels, not necessarily lethal, not even dangerous, but inexcusably stupid and unnecessary. Please consider the following three examples.
My telephone:
This is my telephone and answering machine with its built-in caller-ID feature. When a call comes in, the alphanumeric display shows the caller's name, the caller's phone number and the date and time of the call, but only while the phone is still ringing.

Once pickup has occurred and my stentorian greeting message starts to play, all of that vital information vanishes and is replaced by the utterly useless line "Call Answered".
I've gotten slower of foot over the years so when the phone starts ringing and I finally manage to get these old bones up from the living room sofa, I don't easily get to the phone before the answering machine's message has gone into action.
By the time I finally do get there, the caller data I want to see has been replaced with that useless "Call Answered" line which despite my years, is a fact I am still quite able to ascertain without assistance.
This da.....ed "feature" makes me want find whoever programmed this miserable contraption, grab a handful of collar and yell: "Hey, Stupid!! I know the call has been answered. What I want to know is WHO is calling."
Instead, once the answering machine function has kicked in, I have to stand around and wait for my cheerful recorded greeting to finally end so I can find out if the caller is legit or not.
The proper design of this phone would have been for the caller information to stay viewable and not get replaced by something so utterly useless.
My car key:
What idiot is responsible for designing car keys and key fobs with buttons are so easily pressed by accident? 
Far too often I've had the car alarm sound off or the trunk lid pop open because one of these four key fob buttons got accidentally activated. This key is for my Toyota, but I've seen this happen to a neighbor's Honda too so I know I'm not the only victim of this kind of design blunder.
My car's dashboard:
There is a "feature" in my car's dashboard where the brightness of the dashboard lighting changes automatically versus changes of brightness of the ambient daylight. As I drive through overpasses or alongside groves of trees that cast shadows across the road, the dashboard lighting goes from bright to dim to bright to dim to bright to dim to ..... over and over and over again. To me, that erratically changing brightness is extremely distracting. I would like to have a word with the techno-fool who decided that this was a good idea. The only proper design, in my view, would be to have the dashboard lighting remain constant at whatever level I choose to set it.
I intend to defeat this one though by covering up the dashboard-mounted light sensor with something opaque. If the car doesn't know that the ambient light is changing, it won't be able to respond to those changes.
We'll see how that works out.