I would call it faulty. Seriously faulty. Deck penetration through balsa cored deck that seals poorly allowing water to ingress and cause structural wood to rot so that the rig is in danger of coming down. As it is under the mast deck plate. Balsa cored deck there as well and water gets in and rots the core. Doubtful there is one out there that has not had any issues with this. I know from experience of previous ownership and fixing the issues.And well you should. Chain plates need to be inspected and maintained but I have not heard that the O'day design was weak or otherwise faulty.
Come on Jack! Whats with the straw man accusation? Just how many and what rig failures are you referring to? In 30 plus years I have not found one in our area. So long as the deck shows no moisture the chain plates should be fine. Please tell us what failures you refer to and whatNot wanting to pour gas on the fire, but in my sailing lifetime I have seen more O'days suffer total rig failure due to catastrophic chainplate/bulkhead failure than all other makes combined.
As long-time members know, I've got nothing against odays, and really like the old 28. But their chainplate/bulkhead technique was not their finest hour, design-wise. I would really look over any new-to-you boat, and keep it on the watch list.
The issue is the possible of water getting thru the deck, and the use of structural wood in the chainplate setup. You have to realize that this is not done in all boats, and certainly not best-practice. Many use a system of totally water resistant materials (stainless, fiberglasss) in their method of tying the shrouds to the hull.