[squarefoot]

Can confirm about MicroSD flash cards, they're too unreliable for stuff that must be on 24/7, and get corrupt easily. Good for tinkering projects and media players, not for critical stuff where the downtime needed to pull the card and fsck/reinstall it might not be an option.

[zikduruqe]

I've been running a weather website on a RPi2 since 2014. And it's on the same SD card. MicroSD cards don't get corrupted as much as the interwebz says they do.

[tverbeure]

It has probably to do with the number of unmanaged power cycles. A hobby electronics project will see many of those. A weather station may only see them when the power in the neighbor goes down.

[nsteel]

For something critical, especially one which already involves an external drive, there is zero reason to store your root fs on an SD card. Booting using other methods has been supported for literally years.