[myTouch 4G Q&A, Help & Troubleshooting] Jack_R1:
1) The "general population" got the 2.3.4 update while well within warranty period, so if "excessive flashing" is the argument used for justifying the "bad quality" of the specific eMMC in question - it doesn't hold. All MT4Gs were flashed all across /system partition.

2) The company clearly states that rooting voids the warranty, and we do it knowingly. They don't test the phones or their components for excessive flashing cycles, and rightfully so. We choose to do what we choose to do, knowing that we're the only ones to blame if we screw up something. I believe that the time cleared the "rooted vs non-rooted" failures enough for everyone to understand that some eMMCs of both kinds are bound to fail, and if they are - they'll inevitably fail (as all eMMCs do, but in different periods of time), rooting or no rooting.

3) You should probably remember that eMMCs were new by that time, and I agree that it's most likely a faulty batch, possibly one of the first batches. So? If devices will be replaced upon failure - even failure caused by rooting (which HTC did) - I don't see any case for claiming "flaw by design".

4) eMMC is not an equivalent of BIOS, simply because it's a storage device. Being soldered to the board doesn't make it "design flaw". Design = creation of board and making sure all the components are used within their specific requirements. If a component fails - soldered to the board or not, it's a component failure. Let me give you another analogy: let's say if Atom CPUs are failing when overclocked, is that a design flaw of whoever made the netbook with them? They're also soldered to the board. How does a complaint like "These guys are bad, they're selling us a flawed design that is sensitive to overclocking, even though it's against the warranty to overclock, we should claim a recall" sound? Doesn't sound fishy to you? I bet it does. But why do you think that "These guys are bad, they sold us a flawed design that is sensitive to rooting, even though it's against the warranty to root, we should claim a recall" sounds any better?

5) You're proving my point - if any, the "failed eMMC" users are highly over-represented in the forum poll. I can argue that almost any power user that knows how to root, and had his phone fail after rooting, would come to XDA to seek an advice - and that's probably going to be much more closer to the truth.

6) You prove again that you don't understand the issue itself, right after asking me to assume that it's otherwise. The eMMC is not "bound to fail" when rooted. Specific percentage of the eMMC chips, both "good" and "bad", is BOUND TO FAIL EVENTUALLY WITHIN A SHORT PERIOD OF TIME - rooted or not rooted. And it will ALWAYS be like that - a small percentage of any produced eMMC WILL FAIL shortly after being used. These are essentially the same chips used on SD cards, and the rate of failure is most likely similar, and as you probably know, SD cards fail sometimes. No amount of quality control can prevent statistical spread of silicon lifespan.

7) If you really want to argue "rooting sensitivity" as fault, then you get the strongest possible argument against you, which will probably explain the reason why I dislike this thread:

The manufacturer, as I explained earlier, should design the phone to have all the components working within their specs. To root the phone, you intentionally severely violate the spec of one of the eMMC - power-cycling it without preparation to begin with, and creating a race condition to prevent it from being write-locked when it's powered back on. This violation somehow escapes your "faulty design" argument, but it shouldn't - the faulty design in this case is created by the users that are rooting. And this whole idea of "I'm going to root, even though it voids warranty and possibly stresses one of the system components beyond any possible tests, violating its specifications, and if it sometimes fails - it means I'm screwed by the manufacturer and should get compensation" is well along the lines of "I'm going to buy a hot coffee, and if I spill it - I'll blame and sue McDonalds" way of thinking, which I despise and fight wherever I find - it's not that I like manufacturers.

Anyway, too much time wasted on nothing, not going to argue anymore. If I didn't convince you, and I probably didn't - you can think whatever you'd like to.