Well, there is valid reason behind it. People are generally harming their hearing via this sort of thing. But the problem is that simply arbitrarily limiting volume at the device side is a completely incorrect solution as it assumes all headphones/IEMs/earbuds have exactly the same specifications in impedance and sensitivity. Which is obviously utterly and wildly impossible. Of course, a lot of younger people especially do listen to things too loud for too long at a time which does actually impact their hearing over time. For that matter older people do too. So these laws exist ultimately trying to help people. They just happen to do much more harm than good is all. Not everyone uses really cheap super low quality IEMs that came with some $5 MP3 player from China or something. Since not all devices are the same, the limitations actually don't work right and ultimately limit far too much on most real devices under the intention of protecting from dangers with the cheapest, lowest quality devices. Now, the biggest reason Nintendo is doing this is likely to specifically meet those European laws. A lot of companies do find it easier just to use the same hardware across all such devices and change only the minimum -- this is just basic business in that it's cheaper this way. I suspect, though, that at least in part Nintendo may at least still agree with the basic idea. As I said, a lot of their audience is younger. Don't forget they go to extremes like having the original DS (does the DSi do this?) boot up every single blasted time with that stupid warning message. (BTW, FlashMe can bypass this if anyone still uses a DS. I don't believe there is or ever will be a FlashMe for the DSi however. It was mostly intended for running NDS code from slot 2 devices which became unnecessary when they figured out how to make slot 1 devices work. Not just outdated, but inapplicable on the DSi.) I still suspect Nintendo implements the volume limiting far more willingly than most among other such things.