If you can't come up with an argument against that then you're not trying hard enough. The most obvious is that sharing a mod is free speech and ought to be protected as such.
It's also unclear how mods contribute to copyright infringement in any meaningful way. I'm having trouble finding details about exactly what Neimod's mods entailed, but most mods I have experience with require an existing copy of the game.
Information products require artificial scarcity to be economically viable.
If freedom of speech gives individuals a license to say anything in any medium, then this means that artificial scarcity is inconsistent with free speech.
If artificial scarcity is immoral, then all information products are immoral.
(Note that as a practical matter I suspect that Nintendo only cares about "hacking" insofar as it undermines sales. I can't see why they would care about people modifying the games or equipment they own. I can totally see why they would care if someone invented an SD card cartridge for the 3DS that allows you to run every game ever written from it. Such a device, if mass produced and sold for profit, is clearly intended for piracy. Moreover, its easy to see how such a device is parasitic on the platform itself, so that if Nintendo didn't do something about it then there won't be a Nintendo.)
There is a huge difference between the speech of sharing exact copyrighted material, and the free speech of sharing methods of running whatever software you want on some hardware.
If the later is not allowed, this very comment might be illegal, as I'm telling you that such a thing is possible.
That link doesn't work. Okay, I admit I don't know much about the modding community these days, but back in the day it used to be ALL about enabling you to play the files you just downloaded. What do mods do these days? I admit that if someone is selling a mod that lets you, I don't know, change the sprites around in your favorite game, that would not affect N's bottom line and it would be a big problem if they confronted people about something like that.
If you can't come up with an argument against that then you're not trying hard enough. The most obvious is that sharing a mod is free speech and ought to be protected as such.
It's also unclear how mods contribute to copyright infringement in any meaningful way. I'm having trouble finding details about exactly what Neimod's mods entailed, but most mods I have experience with require an existing copy of the game.