Isn't the whole point of open source to allow anyone to make it themselves?
I see this debated in the Pixhawk circle quite often. The software developers get all upset that chinese vendors used the schematics to produce their own products (??? isn't this the whole point). The 3DR(American) pixhawk costs 2-3x as much as the Chinese version (many wouldn't even own a Pixhawk if they had to buy it at those inflated prices). While the developers make all these claims about how their product is QA tested, they still have all the problems the chinese ones do (or one could say the chinese version has all the problems inherent in the design).
For example, the 3DR version had IMU1 problems because the design had the chip too close to the edge of the PCB, and the vibrations from cutting ruined the chip. The American version has that issue, but the newest 2.4.8 chinese version moves that chip inwards. Wait- the chinese improved upon the design, shocking! The american developers that rip into the product non-stop never mention that.
Or the IMU2 problems with the chip stuck in a brownout state (apparently a very common problem with the LSM303d accelerometer). The original open source design doesn't provide proper discharging of the sensor rail. Chinese fixed that as well
Clones? That isn't very accurate terminology. More like "forks." The 3DR Pixhawk left many issues unresolved, years after they were discovered. Now 3DR has stopped making the original Pixhawk, so if it wasn't for the Chinese forks, there wouldn't be any more. That doesn't get mentioned as a plus either.