This guy is not a frame builder, he's an assembler. Not a joint in sight that's NOT going to fail in a couple of years. At least is REALLY wood and NOT just plywood and pine board.
All butt joints - no mechanical joints at all. The glue and staples are not strong enough to handle years of wear and tear. You need to at the bare minimum have dowels or screws to get longevity out of those types of joints. The best I can say for this is it is at least all solid wood. Though, from the looks of it, it is all SPF wood so it might actually be stronger in some places using plywood (where the forces are perpendicular to the surface of the wood). This is a quantity piece of furniture. The benefit here is simply that it can be made quickly from common materials from semi-skilled laborers. It fills an economic niche, and is usually priced as such. I think the hate here is that people value custom furniture less and less because of things like this and people love to hate things. Oh well :)
It is never too late, I'm a carpenter and i have started leaning upholstery here on youtube, and let me tell you this.. I'm not doing that bad and I'm enjoying every minute of it!