So, as a thin end of the wedge, may I present a humble example of unusable UI which could have been improved immensely by a more sensible textual element.
This is a package of frozen green beans. There is a small but fairly noticeable, if one is looking for such a thing, indication of how/where to open the bag. Unfortunately, the arrow points to nothing. There is no perforated tear-line, no notch, no tearable seam. When they say "Open," what the hell do they want me to do?
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So, it's not the end of the world, not even on the order of software difficulty, but it's a symptom of poor customer-centric thinking, isn't it?
So. I promise to update more regularly.
Adieu till then.