So, in the context of this thread where chinanmashroo is trying to find a blade and does not want Yinhe, he doesn't really need a reason. If he doesn't want something from them, that is enough.
But by all means, go and make a thread asking people what they think about the quality of Yinhe as compared to other brands. If you really want information on that, that would be what to do.
I have a feeling there is stuff that Yinhe makes that is lower quality and costs very little, but is still quite good for what it is like Der_Echte's favorite Yinhe Galaxy 896 blade. For $16.00 USD it is amazing. As good as many blades in the $30-$50.00 range. But definitely not as good as anything I can think of in the $80-$100.00 range.
What about their higher end products? I tried one of their all wood Rosewood blades and it felt really, quite good. I would use it. Was it made as well as a Stiga Rosewood? Well, it was different. But I think it was made with as high a build quality as a Stiga Rosewood. From the perspective of feel, in most ways I liked it more than a Stiga Rosewood. It did not have the NCT coating and that gave it a pretty nice woody feeling.
But any of these companies can make higher quality goods and lower quality goods. Some things that Stiga makes are downright crappy.
The point is, that is not the discussion the OP was trying to have. He was looking for a blade and did not want to bother with Yinhe. So, no need to try and defend the quality of Yinhe products. No need to discuss the merits of wanting something or not wanting something because of what the pros use.
I use a Tibhar/Nexy Kim Jung Hoon blade. No pros use it that I know of. But it is really nice. I also have an OSP Virtuoso Plus. I don't know of any pros who use that either. But man it is good for me. But, if someone wants to use a blade because he knows there are top pros using it, that is his business, even if none of us are top pros.