Or at any other time ? Admittedly it's a delicacy I've never tried, whether traditional or vegetarian but I'm interested to know if haggis has much reach into Mumsnetville.
I don't remember Burns Night (or Week) being an event in the hospitality calendar until the last decade or so. Then again, I'm in Yorkshire so I expect it's different in Scotland. It's a way for the trade to start making some post-Christmas brass in the traditionally lean month of January.