This may be true, but it's really a bad thing for ergonomics. While changing your position is vital, you still need a real work area. Having a proper adjustable height desk + large monitor + ergonomic seating is a good idea. Whether that goes in a corner or in a special home office, working a full day from the couch on a laptop is terrible for your health.
A few years ago this might have been dismissed as a first world problem, but I really hope the tech scene startups dedicating more time and effort into the ergonomics of working from coffee shops in the next few years. Everyone knows what we're doing [working for too long without breaks, in unergonomic positions on laptops where the screen height is far below eye level so craning our necks] isn't great, yet everyone does it.
