In some disk-array configurations, it can be important to match the firmware version of all the drives used for reliable performance. SATA disks oriented at consumers regularly have large changes made to the drive firmware, sometimes without a model number change. In some cases, it's impossible to revert to an earlier version once you've upgraded a drive's firmware, and newer replacement drives may not support running an earlier firmware either. It's easy to end up in a situation where you can't purchase a replacement for a damaged drive even if the model is still on the market.
If you're buying a SAS drive, or one of the RAID-oriented enterprise SATA ones, these tend to have much better firmware stability. This is part of the reason these drives lag behind consumer ones in terms of maximum storage capacity. Anyone who regularly buys the latest, largest drives available on the market can tell you how perilous that is-new drive technology is rather unreliable. It's fair to say that the consumer market is testing out the new technology. Only once the hardware and associated firmware has stabilized does work on the more expensive, business-oriented versions, such as SAS versions, begin. This makes it easier for the manufacturer to keep firmware revisions stable as new drive revisions are released-the beta testing by consumers has already worked out many of the possible bugs.