BTW I've seen plenty of Seagate HDD fail and have a few of them which developed bad sectors laying around. Also it's not like Seagate made one bad series and then it became OK. They repeated it several times. Backblaze buys any HDD they can get cheap, they will buy crap as long as cost benefits outweigh losses due to failure rate. IIRC they once made a statement about that.
Yes, and they also put lots of cheap consumer grade drives in large disk arrays where they are exposed to constant vibrations for which they were never designed for.
Those bad drives which I have were not exposed to anything, one HDD per office computer at my work.
Fair enough. I still question how relevant this is for making general statements about a brand's overall reliability.
For example, larger offices tend to buy business PCs from large vendors like HP and Dell, which often use drives that come with non-standard firmware. Also, if a drive fails, the replacement drive is often a refurb or even used drive, not a brand new one. The failure rate here has no relation to even the same original drive that's sold on the open market.
In addition, some desktop hard drives are specified for an average of 8 hrs use per day. If that's exceeded (which in offices it often is) then this may well impact the failure rate you see.
If the drives were bought on the open market, there are other factors which affect failure rate. Are the drives OEM or retail variants? If OEM, are they official or grey market? Are they all from the same batch or from different ones? Date codes? Places of manufacture? What were the firmware versions? And so on.
Just seeing x number of drives failing means zilch for how reliable a specific hard drive manufacturer's products are.