I agree acat I'm self employed and bar the 'what do you do?' questions and the odd bit of sharing my Etsy page I don't talk about or share pics of every single business meeting I have because well... that's private and confidential info.
I think I've gone as far as tweeting a coffee loaded with syrup because a train was delayed making me late for a meeting and me moaning it was packed 
or the DC stealing my phone and missing a call! but I have public and private accounts so it'd never go on the work account at all. That's private cheering not something you should share with clients at all.
I think some of the oversharing is the whole 'fake it until you make it' mentality. If they (FB friends) believe its easier for you to believe it and the viscous circle keeps going.
I do wonder if this is part of the MLMs strategy. If you get your zombots recruits to plaster it all over social media they have to keep at it because when you stop your friends and family will be the first to ask 'what happened to the great business?' and you are left feeling shame/guilt for failing and not making it work. Its keeping up appearances of the most sinister kind because its playing on peoples sense of failure and new mothers are the most vulnerable, and likely to feel a sense of failure, so are often the main targets because of their need to not feel like they are doing fuck all to contribute to the family kitty.
These 'Life coaches' are using psych 101 in large chunks of their courses using manipulation and techniques to overwhelm by providing way too much non-info. Think of it like an overly wordy book, Barbara Taylor Bradford comes to mind, I read one of her books and a chunk of it was so wordy and going into irrelevant details I completely forgot the start of that chapter and which characters were present. That's what these coaches do just in a public arena and people buy tickets.