I'd say that isn't any issue with the manufacture just a case of poor boatmanship. By that I mean the anchor has probably been sitting in a puddle, maybe in the locker, or has had the bottom wet for a lot longer than would normally be expected. I say that as yuou mention the rest of the anchor is still pretty good.
Whatever happened it hasn't happened quickly and should have been seen and the issue dealt with a long time ago. Hence the boatmanship comment. That is scaly rust and scaly rust takes quite a while to happen. That is assuming the galvanising was fine and I've no reason to think Spades galvanising is any worse or better than anyone else's. Even if the galvanising was worn off, which can happen inside 2 months if in some bottom types, that amount and type of rust took a while to get that way.
Seeing anchor with rust like that isn't uncommon. It's very common on secondaries keep in anchor locker
and not used for a year or 3. I'd all most be confident in saying that has been at least 18 months probably more in the making. I'm 100% sure it should have been picked up sooner and dealt with by at least a hard wire brushing and some cold galv.
with anchors - the more you use them the less they will rust. Includes anchor chain as well.
Seamanship is handling your boat and boatmanship is looking after it.
 damn pushed the wrong button again, sorry.