I don't think they're trying to pull a fast one on consumers, but I think that when you set a warranty you're doing it based on probabilities.

Let's make a hypothetical example. I'm selling an SSD and I say, "it's waranteed to N bytes written". Let's say that I'm magically omniscient and I know that 5% of drives will fail at 0.75 * N bytes written. Let's say that I also know that over the first 5 years of a drive's use, only 1 in 10,000 drives will go over 0.75 * N bytes written. So, I know that I'll be on the hook to replace 1 out of every 200,000 drives I ship - 1 in 10,000 is a "dud" with only 75% of its rated lifespan, but only 5% of users will exceed the lower "dud" failure level. Most drives will reach 100% of their rated lifespan.

Is that pulling a fast one on consumers? I don't think so. It might be a tad optimistic, but most drives will meet the spec and almost no one ever comes near the spec.

Now, Chia comes along and it means that way more than 1 in 10,000 will hit 0.75 * N writes. Let's say Chia becomes 50% of drive demand. Now it's not 1 in 10,000 drives exceeding 0.75 * N bytes written. It's 1 in 2. Now I have to replace a drive for every 40 sold - that's a lot different from replacing a drive for every 200,000 sold.

Let's make another hypothetical. Let's say that Chia's write pattern creates additional wear. I've made my drive under the assumption that you'd be using it and then there would be down-time for it to cool off and then you'll use it again. I haven't made it assuming that you'll be maximizing write throughput as fast as you can. I'm assuming normal access patterns which offer the opportunity for the hardware to cool.

Let's make another hypothetical. I've made my drives assuming they're going in computers that will be sitting in someone's laptop or desktop in their home at around 70F in a unit with reasonable thermal properties. Now Chia farmers are buying the drive, sticking them in the cheapest place they can put them without cooling (where people don't really live) and trying to maximize their return. I wasn't expecting the drives to be run in a 90F environment at 100% write throughput 24-hours a day!

Let's make another hypothetical. Let's say my drives are 100% to spec. They fail at N writes. You're a Chia farmer and the drives perform according to spec. However, if you could get me to replace them with fresh drives, you'd earn more money. If you can figure out a way of making it seem like they failed early, you can get free replacements and cut your costs in half! Yes, this is fraud, but I'd guess that there are a lot of Chia farms that might not worry about that.

When you write a warranty, I think you are writing it knowing that some of your drives will fail before that guarantee. You set it at a level that most of the drives will be able to achieve and you set it with the knowledge of how many claims will likely be made based on how consumers use the drive. Chia represents a huge change to the second part there. Like, my car has a warranty, but one of the assumptions in that warranty is that I'm not likely doing stupid things with my car like running it at the redline constantly. If RedlineCoin becomes the next big thing, it isn't unreasonable for an auto maker to say, "yea, our warranty applies to normal usage for 50,000 miles, not 50,000 miles driving at the red line".