I don’t remember if it was John Rhys Davies’ inspired performance as Gimli that set the trend of Scottish-accented dwarves, or if that came about before the Lord of the Rings movies and he just did it better than anyone else ever. But it seems to be the standard now – Dwarves sound Scottish. Tolkein’s Dwarves should definitely not sound Scottish. They use names that are either very influenced by or directly stolen from Old Norse mythology, and the Khuzdul language has Semitic roots. A Dwarf accent should sound like an Arabic viking.
Just found out about a new LotRO Store dwarf-only cosmetic item today. Bought one and made sure all my dwarf characters made use of it. Here’s Gordur, the Minstrel, trying to look like Glenn Danzig.