I think there are two things happening. 1. There is an underlying assumption about fit and finish of Swiss parts that
may or may not be true. I have seen both Swiss and Asian movements that worked extremely well and with the 6497, the parts are mostly if not completely interchangeable. On the negative side, some of the materials of the Asian movements seem to be of lesser quality and therefore, some of the issues I personally have had with these movements have been metalurgical in nature. YMMV
2. There is some arrogance in our hobby that forces us (Myself included) to shun Asian movements in general, even in Reps. On some watches, you cannot properly replicate the functionality of the original without going Swiss but it tends to get expensive.
Ask me about my 250 Panerai conversion.
For me, it is mostly number two. There is something about knowing that even though I did not pay 5K for a watch, it has a
very similar, if not the same movement as the $5K watch but only costs a fraction. I buy watches, both GEN and Rep because of the look and the movement. Therefore, it makes sense in my mind to go Swiss...