YANBU
We had this on Sunday when the people whose garden backs onto our garden decided to have a bonfire going for 5 hours! Our garden was thick with smoke and ash and we had to stay in the house with the windows closed as the smell was so disgusting. We didn't say anything, but we definitely will if it starts to become a regular thing.
I'm OK with BBQs as they don't last long and generally are not offensive, but I can't see any justification for lighting bonfires these days, ie, there are plenty of other ways to get rid of waste.