No, there's lots of things better left untouched. You only create an emulator or run a private server if you believe there is room for improvement. But even if someone makes an Emulator for league of legends, we dont have the means or tools for custom content. All it would promote is piracy of skins, screwing riot out of money. There's no real extras that would be added, we can't make our own champs, we can't make our own skins (maybe) so what point is there in having an EMU. Free skins and runes? That's useless that just fucks over riot.
So yes, there are times its ok to say no. MAINLY when the EMU just promotes piracy. It's like when geohot created his jailbreak for the PS3 it was focused on running priated games, not allowing homebrew. Thus, i don't like Geohot he promotes piracy instead of being a homebrew activist.