I suppose you mean the other way around? Otherwise, what's the problem with selling a higher RPM device as a lower one? Isn't higher RPM better? (Genuine question, I don't know much about HDD).
They also draw more power, which might mean they simply don't work properly in some low-power devices, or mean that any UPS someone might have one connected to will not last as long as they expect during a power interruption.
WD Red is marketed for NAS/storage, where it's not uncommon to have 4/8/12/16 drives in the same chassis where noise/heat becomes a very different problem. It turns out that the drives generated the same heat and consumed the same power as 7200RPM drives, while the data sheets were outright lies and BS. WD decided on double down on the BS for several months, and only recently released new SKUs where the specs matched the marketing.
They sourced drives from former HGST under WD but 5K4 we’re not available so marketing rebadged 7K2 as “5400rpm-class” and lucky buyers were hit with better performances.
Sort of. The WD Red drives outperformed actual 5400 drives but underperformed other 7200 drives by a large margin (180MB/s vs. 230MB/s), while not necessarily offering heat or noise benefits that matched. My current 8x8TB WD Red Unraid build will likely be the last WD drives I buy for a long time.
This is the third such major scandal from WD in as many years. First, selling SMR drives as CMR. Second, selling 7200RPM drives as 5400RPM. Now this. They've lost a lot of credibility, and I don't see any of the other manufacturers having issues rivaling WD.