I can't imagine having to sysadmin a bunch of raspberry pis in a serious "production" setting with all the reliability problems they have, that would be godawful, you'd go through a brace of SD cards every month
First some comparisons. Kids are seriously rough on technology. We had a fleet of about three hundred laptops, two hundred iPads, and two hundred Pis in the junior school.
In a year, we'd end up with about a hundred laptop screen replacements, two hundred keyboard replacements and about a hundred hard drive replacements. About ten "I accidentally dropped the laptop in the river"s. We'd cycle the laptop out for a brand new one at four years, if it survived.
In the same year, about sixty iPad screen replacements, ten or so battery replacements, and twenty or so river dunkings. Only ever had one hard drive failure, apart from water damage, but the iPads were on a short two-year upgrade cycle.
The Pis were used for the robotics clubs (optional) and programming (compulsary). Pis aren't great for kids and robotics due to lack of protection on the pins for dumb mistakes. We had about twenty fizzle the mysterious smoke every year. About twenty more than experienced SD card failure in the year, usually related to yanking a power cord, not direct write failure. We also had a couple students a year who snapped theirs in half.
All in all, the cost of maintaining the Pi fleet was negligible besides the rest.
The cases are sealed, but they're still permeable to stuff you wouldn't let near your computer because you have a slight respect for technology.
I found fungus growing inside more than one iPad case, usually directly in the boards.
The semantics on this one aren't worth exploring.
Is there some more fundamental hardware damage that occurs when USB devices are unplugged without prior warning to the device itself?
2. SD cards can wear out (i.e. too many write-erase cycles) regardless of the filesystem.
3. SD cards have controllers running firmware, doing things like write levelling and bad block remapping. Some cards have bugs, and if the card is lying to the OS about a write completing, or if the remapping table is less resilient than the filesystem's journaling, you get problems even if the OS and everything on it is perfect.
4. Problems like pins with poor connections and power supplies not providing enough current are exacerbated, as microsds have no space for power capacitors and few SD card holders are rated for hundreds of insertion cycles.
5. SD cards start out a lot cheaper than SSDs (easier to find a sub-$10 SD card than a sub-$50 SSD) and the market is awash in fakes
All these problems look very similar - "My RPi stopped booting, I replaced the SD card with a freshly written one and it started booting again" - making forum anecdotes and user bug reports hard to rely on.
Gauranteed 500,000 writes, probably much more, but they have "mission life" quoted at ten years on the vendor cert, so will be ditched after ten years and replaced.
Apparently they are a whole different type of logic design, hence the cost. Even the no-name or branded equivelent I could find were close to $1k each, but given use in safety service we went legit all the way anyway.
Anything with the magic S word stamped on it seems to double in price...
And yes, SD cards have flaws.
My question was: if I turn my computer off every day by yanking the power cord, I expect nothing to break, so what am I missing when people seem so wary of doing it?
(Recall that this was all in the context of a parent comment lamenting a lack of a dedicated shutdown button on the RPi.)
That said, I don't think the Pi was ever designed for "serious" industrial usage; I don't think the production runs (or the foundation) could support that, without undoing the core mission.
That said, I agree kids are rough on any technology.