Mining wasn't the issue. It's in the article. Improper warehouse storage conditions.
I've done more digging into it and apparently it was caused by using a heat gun to reflow the die after it failed when mining.
BTW if we do take what the news sites are saying as gospel, IE this.
However, the main issue was not the fact they were used for mining, as many post-mining cards are used by gamers around the globe every day. It is the humid condition that these cards were kept in, that might have been the cause of the problem. Prolonged storage of graphics cards in a warehouse with high moisture is a very plausible explanation for GPU cracking.
It's an oxy moron.
It is mostly the conditions that mining cards are used in that causes the failures and problems. As well as the abuse they receive that will drastically reduce their life.
As an example, it mentions humidity. A lot of mining farms are in hot countries. Where they will deliberately spray down the floors with cold water which in turn will become airborne moisture used to cool the cards down more. Another classic thing miners do (and is very well documented) is put cards that fail to work into a ultrasonic cleaner to again, squeeze more life out of them. Again, this is not something a normal user would ever have to do to a card at any point unless maybe they spilled something on it or spilled coolant on it if they were say, water cooling.
I suppose it depends on how people look at it. However, abusing something using it for a purpose it was not designed for will always cause a problem, no matter how much miners want to butter it up when it comes time to sell.
It's the same thing with regular farming. You can't just use regular garden equipment for it, you need harder wearing machines and tools. These cards are not designed to be plopped into a mining farm. They are designed for gaming, and at no point does any company spend extra making them harder wearing nor do they add moisture proof informal coating to them either.