You may be right,i have had one apart and it is a 9 element lens and it is being used by quite a few pros i know using the hero 4. I am impressed with the work they do and they teach aerial photography and spend time time Eric Cheng and others from Adobe etc.You must be naive to believe that the $150 ( $ 10 real price from China) ,used for surveillance cameras cold produce the same picture quality as 9 elements sony lens .
Most mind-blowing GoPro videos are heavily edited or GoPro with special cage and good quality lens is used.
I would say the GoPro processor and the sensor would be same quality as Inspire camera one ,but that's all.
so if they are wrong about the quality i would not know as i am not as good as they are.i have won a couple of awards years ago but they are more knowledgeable than i so i tend to trust them.
i will say that i put one on my go pro and did not think it was as good as the stock lens and i returned it for a replacement.
i will be putting the new lens on mine after t day.
hopefully it will be as good as i have seen example of.