I agree that this is not a huge problem, but there are more than just a number of cases. These can have different reasons:
1) The CO does not know where exactly the border is, e.g. GC4KTAG (the CO kindly corrected the attribution from Croatia to Bosnia and Hercegovina after I asked him to); GCGJJ8 (an event long ago but funny because even the title refers to Belgium although the co-ordinates are in the Netherlands)
2) The CO wants to keep all caches of a cross-border series in a single country, e.g. GC6KNJ7 and others of the series, originally attributed to Belgium, but kindly changed by the CO after I had asked him to.
3) Political reasons, if the CO wants to make a political statement, e.g. GC63JJG, and, perhaps, those archived UK caches situated in Northern Ireland, e.g. GC17QPG.
4) Deliberate wrong attribution due to other reasons, e.g. the recent discussion here: https://project-gc.com/qa/?qa=20124/planning-mystery-coordinates-considered-virtual-physical
Sometimes, the reason is not clear, e.g. GC1EXW8 (attributed to Belgium, co-ordinates in the Netherland); GC11BNQ (header co-ordinates clearly in the Netherlands although attributed to Belgium).
Sometimes the cache in reality is on the border but the co-ordinates point to the other country, e.g. GC3Q3FQ (attributed to Serbia, in reality intended to be on the border, co-ordinates in Bulgaria). GC4MKJT might be such a case, I don’t know what the situation is there, but the co-ordinates seem to be in Zambia, the cache is attributed to Zimbabwe.
In other cases it might simply be a fundamental error when it comes to the co-ordinates, e.g. GC6V6QT, GC6M0WN, GC7DYF9, GC5Y43Q, GC6FF1G, GC6MQCK, GC537NE, GC4A1N7, GC59FNJ.
Or a strange mistake with the country, e.g. GC4E4E1, GC1KAVM.
Or temporary insanity, e.g. GC83152.
Or even some weird kind of humour like in GC6DFRX, GC6CVC9 and the rest of that April fool’s day series, which, harmless as it may seem, leads to maps – when running a search for caches in that country – showing the entire world. If PGC overrode the wrong country attribution we would not need to scroll and enlarge the map every time till we see the country we really want to see.
Summing up: normally CO’s with wrong attributions do understand the issue and correct it if asked to. Therefore, as long as I don’t come across a CO who would not be willing to correct a wrong country attribution (thereby distorting my geographical statistics), the biggest practical problem in my view is the maps issue.