I responded with apprehension and gave an example of a similar initiative that Nintendo has already shipped [0], which has been widely mocked, and I explained why these sorts of nagging notifications are a tricky balancing act (the product doesn't know the context of your use, but can only guess, and it is grating when it gets it wrong).
It wasn't widely mocked. I have met numerous people who played Nintendo games with this warning and seeing some neckbeards on the threads you linked I had never seen anyone complain about it. Most people just take a break or don't play for extended times to even see the warning.
Only 'neckbeards' had a problem with it? That's simply not true, and the links I provided are full of people explaining why Nintendo's execution was flawed.
[0] https://gamefaqs.gamespot.com/boards/997614-nintendo-3ds/747...
https://www.neogaf.com/threads/does-nintendos-oh-youve-been-...