It's also interesting that dwarves now speak with a Scottish accent ever since the Jackson films - including in other fantasy films and games.
Especially as they tend to be seen as displaying certain disturbingly anti-semitic traits - the destructive love of gold, the large noses - and Scots are also in the context of the UK caricatured as miserly.
An interesting, and somewhat dangerous choice, by Jackson. I don't know if there was a precedent for that, or if he picked it himself.