It is weird because we are talking country specific. If you are going to make a list of the best performing movies in country you will always look at admission and the local currency because that what the country uses. USD is just a conversion for the global boxoffice but has no effect on the 'all time' tittle associated with a specific country. I mean look at the UK, the pound was once 2x the dollar, no clearminded person is going to make a list saying x movie is the number 1 in UK because it had a 60% currency advantage.
And yeah even in countries own currency you have inflation and ticket price hikes so even those records will be call in to question (the same as we do when new DOM boxoffice records are set).
I do agree that the money is the most important thing for the company, thats why we have global gross list in USD and compare all movies worldwide. But for recordholing in specific countries USD has no real place and should only be used if there is nothing else.