Well, seems like a match made in heaven from a quality perspective if it happens
Well, the only reason I stopped buying Seagate was because they reduced the warranties to 1 year, which makes me nervous (unless you count retail kits or super-expensive drives). I'd say I've bought about 150 disks in ten years, about 90% of those were Seagate, to my knowledge 5-10% of the 150 have failed (in or out of warranty).
So you've had a bad experience (or two) with Seagate. Once up on a time WD were a lot more popular with OEM builds, so I saw a lot of WD disk failures and very few Seagate failures. Of the WD disks I've bought (very few, approx 10 and only in the last 3 years I guess) the one that failed screws with the percentage of reliable WD disks in my experience somewhat. On the other hand, someone may have been in a similar position to me but mainly bought WD disks and had a similar experience to mine with Seagate disks but with WDs instead.
A friend of mine probably has probably only bought ten hard disks in ten years, max, and stopped buying Seagate after he had a few quick failures.
My point is, perhaps your experience isn't definitive. I'm not saying mine is either. As far as my personal computer is concerned, I haven't had a drive failure (or something that might qualify to be returned on warranty) since the IBM DeathStar around the year 2000.
Back to the topic, OCZ has a bad reputation certainly on these forums. Assuming that's a fairly definitive experience (it might not be though), then Seagate buying a manufacturer with SSD building experience but is having problems with their QA, I suspect Seagate has a lot more experience with doing QA right, so it sounds like a fairly good match based on that logic.
If Seagate really was so terrible, it wouldn't be the only HDD competitor alongside WD.