That doesn't mean they're going to inherently be coming into your house and whispering in your ear every time you touch the NX. If you don't want to bother with those people, then doing buy BF and turn on the voice chat. I doubt people that would only buy a NX for BF (assuming they forgot there are other platforms that will probably have more things they want) will be overlapping into other online communities tied to the NX. Even if they did, they'd probably only overlap into other games that would be along the same lines as BF.
I PC game a lot. BF and CoD exist on PC, but I can safely say I haven't had to deal with any of those people just because we use the same platform. I play very different games that won't typically attract those people. Just live and let live. As long as you don't go out of your way to pester those people and their communities, I doubt they will come over to bother you and yours. Sharing a platform doesn't mean sharing a community.