Title should be read cheap imitation carbon. You can predict how a metal would perform at a glance, if you are familiar enough with the material and its grade. Even to someone extremely familiar with carbon construction, there's very little you can predict as to how it would perform until you have physical possession of it and can run it through tests like in that article. You can't even trust the weight figures, pictures, and test data, as they can very well lie about those too.
There's some decent finds out there, but the target customer pool that would do well with it is very limited (typically scrawny casual/beginner-intermediate skilled folk). I'd rather gamble on second hand carbon from a reputable brand, over no name carbon. Else, I'd stick to brands that actually hire real engineers and have generous warranties, waiting for deals if it's out of my budget.
On the other topic: carbon rims are a part of the 29er revolution. Stock 29er wheels are weak, flexy, and heavy. People have resorted to using 29 wheels similarly fashioned to what people on smaller wheeled bikes use for DH (ex. Stan's Flow rims), to get the stoutness they desired, but that didn't solve the weight issue. 29ers are what helped drive change to meet demands, including thru-axles, tapered steerers, short HT with internal style headsets, tubeless, light tires, varied fork offset and other geo workouts like bent seat tubes being more of a norm, higher quality short travel suspension, etc. It drove money spent on R&D through the roof, and those that didn't invest fell behind in the 29er race. They decided to take all the new tech and put it into smaller wheels to stay "up-to-date" (inc carbon rims), yet not need R&D to create a bike that rode well, unlike the crappy me-too 29ers that ruined peoples' impression of 29ers.
