It's all in the ear, I think. There's a maudlin kind of song called "Old Scotch Mother Mine", written about 60 years ago Old Scotch Mother
A kind of pub song, sung after a few drams but always with the adjective 'Scotch'. I've heard it sung hundreads of times (in Scotland) but recently a young lady sang it as 'Old Scots Mother Mine' and it sounded so prissy, mim-moued, and anglified. So I think there are occasions when language can be modified and words in use for over 200 years can be used without creating a furore. The even older adjective was 'Scottis' paralleling 'Englis'.