People see bikes they like, if they are reasonably priced and work for what they need, they buy them.
Sure, some people look to fake they own an expensive bike which is a bit weird, but not most.
Most who buy these kinds of frames ride them as unbranded and enjoy them not caring about brand names, and would never consider paying the price of the original. It’s really not that complex. I don’t see why people get so upset. Those who would buy the original would never consider the clone.
IP theft is not great, the customer for this bike is not the same customer as for the cervelo however.
I don’t care what people ride. So long as they are happy. It’s not my business. I do find bikes like this one interesting however.