Sure, there can be negative effects of spending too much time on social media, but who defines "too much"? This kind of month-long fast suggests that ANY use of social media is causing negative effects to ALL who use it, so we all should eliminate it to go do "real" things. This ignores the fact that for some, connecting to people socially through the Internet is just as real as anything in their non-virtual worlds, and that this isn't automatically a bad thing. People suffering from physical disabilities, illness, crippling social anxiety, agoraphobia...or even people whose business depend on social media...are they also "addicts" who need to break their bad social media habits?
It can be a welcome, healthy break to unplug from devices, from social media, from technology once in a while, because yes, we can become a bit lost in them at times. Too much of a good thing can be a bad thing. But a much more realistic break is a day or two. The people who would even consider avoiding social media for an entire month are the ones who don't need to in the first place.