Hey lighten up.
Overseas means a lot of things (certainly not just Europe) - most cruises go to Mexico (east or west coast) and the Caribbean.
I totally agree that in many of those places OTC drugs can be of much lower quality - especially in Mexico.
Furthermore - you can only buy MOST OTC drugs including even antacids, aspirin, band-aids etc ONLY in drug stores (pharmacies) in most of Europe and Mexico, meaning the average port stop or small town probably won't have anything you need available.
Here in the states a gas station or grocery store can sell aspirin. Not in France, England or most of Europe or Mexico.
It is a good point - do your homework before you go anywhere and in any case, you can never go wrong bringing your own stuff - you get what you expect and you have it when you need it.
Good advice, BPC.