OH!
I didn't realize that a Wifi network (a, b, g, AND n) was the same as a Bluetooth network, which is the same as both a CDMA and UMTS 3G network, which is obviously the same as an LTE, WIMAX, and HSDPA+ 4G networks, which is compatible with both the 700Mhz and 900Mhz spectrums, which also works with infrared, AND the IEEE spectrum. That isn't even all the wireless networks out there, and then there are still wired networks.
But those are all the same right??? It doesn't matter that Nintendo could being using a proprietary radio for the 3DS network or three different radios for the three different regions? But, we don't yet know any of this (maybe we will in a little while).
And beyond all that is Nintendo alleging that not all games are going to be region locked. Whatever your speculation on why Nintendo is region locking, not all games are going to be locked. All those arguments you gave mean little because, NOT ALL GAMES ARE GOING TO BE REGION LOCKED. You have no idea (and neither do I) which games will be locked, nor can you know from the outside why they will be locked. The actual evidence I referred to would be a region locked game. All of this, even my presumptions (besides the fact that networks are all different, and not all games will be region locked) is just speculation.