This is why I personally am very reluctant to the sharing of well founded ideas on platforms such as github, in hackathons, in competitions, in recorded speeches etc. How unlikely it may seem, this is a great example that ideas with traction do get picked up and copied, and the originator screwed over. I honestly sometimes feel as if the openness is pushed and saluted, but with the ulterior motive to skim for ideas.
Yes, I agree, and everyone (devs) should think about who they’re really trying to make things easy for.
If you simply say follow the ISO standard you’re essentially making it easy for yourself and hard for the users. Sprinkle that with a drop down day picker as in the example, and you’re really in control of what the input will be. Not much chance of faulty input, right?
However, the ISO will not be relatable for many people and the drop down is a UI nightmare.
The user will be spending much more time with the form than devs (runtime), so this of thinking should definitely be avoided (during programming time).