anselhelm
SSDs and HDDs both can suffer from firmware bugs which cripple a drive (*cough* Seagate *cough*) so whilst I understand where you're coming from, I would still opt for a large SSD at an affordable price given the chance.
Yeah, both can outright fail of course and you probably know what I meant specifically but if not, I mean an SSD can irrevocably wipe an entire drive in an instant, no chance of recovery. A HDD simply isn't capable of failing so spectacularly, so quickly - if the PCB dies it can be replaced, if something mechanical dies it can be replaced (probably needs to be in a clean room ideally), if the head crashes it might wipe out a few tracks but professional recovery can still salvage most of the data, and so on.
If a HDD is failing you'll often get some warning and have the ability to quickly copy important stuff off, even without resorting to the above methods or paying a recovery firm. A firmware bug on an SSD has plenty of methods to choose from to destroy its contents instantly, e.g. corrupting the mapping tables (through unexpected power loss for instance) or just outright flashing the NAND - NAND flashing completes in seconds, it doesn't have to go in and erase every block one at a time at normal write speed like a HDD does. And we've seen it happen on real SSDs because of bugs. It's far less common now they're maturing but it's still going to be a concern.
And then of course there's the issue of data retention, degraded flash can lose charge and therefore data if left alone for long enough, so it's probably unwise to rely on them, especially finer geometry NAND, for archival use which in itself is a far-from-insignificant market. Retention is over-exaggerated for drives in normal use though, the amount of places that misinterpreted a study a while ago was alarming, so much so I actually emailed the source and asked for an explanation, they provided me with this link:
http://www.pcworld.com/article/2925173/debunked-your-ssd-wont-lose-data-if-left-unplugged-after-all.htmlOf course, everything will be backed up anyway, right? ;)
Except professional recovery companies would be out of business were that the case…
Anyway, my point is that the likes of Google, Microsoft, Facebook, etc (and likely organisations such as the NSA, GCHQ and so on) buy HUGE volumes of HDDs for, amongst other things, archival use. That alone drives demand. So sure, if SSDs reach price parity with HDDs (despite claims to the contrary I don't see it happening soon, people assume HDDs themselves are a stationary target which they're not), or even just cheap and big enough for most practical consumer uses while maintaining decent performance, they'd likely displace a lot of HDDs in that segment. But overall it probably wouldn't matter all that much - the market for HDDs would still be vast. Like the comparison I used earlier - tape drives aren't exactly found attached to every desktop any more, but they're not going anywhere for backup use.