Thanks for reading! I agree that taking Internet access from someone in order to provide it for yourself is hypocritical, and against the very ideals of the UN I point to in that tongue-in-cheek opening reference.
That said, when I’ve tried this I’ve noticed that I still see traffic from the other client with the same MAC address when I sniff their wireless data. So it’s not exactly a “restriction” of their access. But I wouldn’t be surprised if you are also causing interruptions for them, too (just as much as I see interruptions in my own connection). I’ll add a note about how by doing this, any problems you see for yourself might also be experienced by the client whose MAC you copied, and let readers decide for themselves how to use this information.