Yorkshire isnt the most cosmopolitan place..
I live in "Yorkshire". Now it depends on where you are talking about. North, South or West Yorkshire. If you just mean "Yorkshire" then you're talking about a "county that is the largest in the UK.
I doubt if any of Yorkshire is as diverse as say London, but it can come close, if you're talking about Bradford or Leeds in West Yorkshire. Sheffield in South Yorkshire is pretty cosmopolitan.
North Yorkshire, where I live, is mostly rural. Hundreds of square miles of nowt but moorland with the occasional town. There's nothing to attract immigrants who need to work.. no heavy industry. Ny town, Scarborough is one of the few places you'll find in North Yorkshire with any kind of industry outside of York itself.