Wow. You are indeed very unlucky. I must have a hundred brushes from dozens of brands all over the world and I only ever had one minor issue (a knot fell out - US-based brand, FWIW - and obviously an extremely easy fix).I still have Simpson brushes that I am enjoying. You may be referring to this post: Your favourite simpsons badger - https://www.badgerandblade.com/forum/threads/your-favourite-simpsons-badger.646111/page-2#post-12463389
If that is the case you may want to read it again. in any case as far as the reason of the bad luck is concerned you need to ask who made the brushes not me.
The companies that I mentioned make excellent brushes, however I have seen several issues with some of the brushes that I have received, from the quality of the hair (look at that picture again), to a knot falling off the handle at the very first shave, poor engraving, prickly tips (on high end silver tips!). The only exception is Zenith, probably because I have only the two brushes that I have recently purchased, however you can simply read some of the discussion about Zenith here and on other forums, and see how many people had a lopsided knots, shedding, losing the top ring or other problems. You can do the same exercise for other brands, you will see that I am not a special case. It happens, they make 'crap' too. Do they have excellent customer service? Probably, but I do not see the point.
However, I don't want to drag this thread further off topic. I was just making a commenting about the 'crap' thing.
I do agree with you that many great quality products are made in China. I really don’t care where something is made - it’s the product itself that matters, and no nation is inherently better at making stuff than any other.