I did this (in an RV) for a few years in my younger days, when starting my first business. It worked very, very well for me and came with the added benefit that I could move my office any time I wanted to be in a place that was more convenient or enjoyable.
I think the motive of this group is to organise people to the streets with bare minimum costs, sounds more like an agenda to show that it's possible than to be a practical working space.