Simple - you can buy fake reviews.
True, but not over 1,700 fake 5-star reviews. So it would appear there definitely were some bad samples out there, but most worked as advertised.
I think biases are clouding judgements here. Just because one or two brands may have top rated products, that does not mean the other brands are bad or destined to fail. Also, when a company produces many products, and some of those have less than stellar reputations, that does not automatically mean every product the company makes is less than stellar.
I don't care what the product is, or who makes it - I never put much faith in user reviews unless there are many that report the exact same problem with the exact same product. Happy users don't complain and many don't bother with reviews. And most reviewers don't come back after they have used the product for a while to write reviews, so we don’t learn how the product holds up over time - a critical factor, IMO. Also, users typically don't have comparable products to compare with for proper side-by-side (A-B) comparisons, nor do they have properly equipped testing facilities or the necessary technical training for a proper evaluation.
Often times you will see products down-rated because it was a different color than shown on Newegg, the Post Office delivered to the house next door, UPS delivered it a day late, or the box looked like it fell off the FedEx truck. So if I am considering a product, I read the user reviews but I don't put a lot of stock in them,
UNLESS as stated above, there are several complaining about the
EXACT SAME genuine fault/defect with the actual product.
As far as bad customer service - I have no reason to doubt other's claims that it is lousy. I can only say they have treated me well. But the truth is, I have rarely had to contact them and it has been awhile since I last did - yet we use Gigabyte motherboards in builds here all the time. We've just had no need to contact them. We also occasionally use Gigabyte graphics cards but more often lately MSI or stick with integrated. I have never used a Gigabyte PSU.
But I will reiterate what I said above, if I receive what I feel is lousy or unjust treatment "after the sale", that sure will affect my opinion of the company too. But my opinion of a company and my opinion of the products they make are two completely different things. Lousy tech support does not mean lousy products.