"Crap shoot with HDDs"... yes, but I think the reliability factor is pretty great for these drives.
Our experiences - with tens of thousands of drives - has been "If they don't die in the first few days, they'll last for years."
This is something I'd love to see MFR's display: "When does your drive typically fail? First 10 hours? First 100? From Year 1-to-2? 2-to-3? Year 5 and beyond?"
The warranty-period should be a great indicator but this is almost a "reserve maintained on-hand" issue - a willingness to hold unsold units for replacement vs. a willingness to recycle unsold units and use warehouse shelf-space for newer products only.
I'll have to find out if we can return a 4-yr old WD to WD, or if it's simply accepted by our distributor and a product is returned from them, not WD. I think that's the case - that WD 'pays' distributors to maintain some reserve (this is a "rebate" as in "we'll cut your next purchase price by X% if you order More within A Shorter Time Frame"). Pushing inventory 'downstream' is how everyone makes money - not maintaining a 'replacement reserve' which can mean, "We didn't sell as many as we produced."