Partly because I hate McDonald's food. Whoppers are one of the best burgers out there. They were better years ago when the buns were actually toasted in the store and the burgers were cooked like they were then instead of whatever they do to them now. But they're still way better than anything McD's has.
I like the new "Satisfries" and liked the old fries as well.
My biggest complaint about BK, probably applies to other restaurants as well, is that they smell like cleaning solution. Sometimes the burgers even smell like cleaning solution, like maybe they just wiped the prep surface with a wet rag, which they probably did.
Many, but not all, of the BK stores are not well managed and are aging and not that well kept up. I'm not sure which 7 stores you own/owned. Are you selling to H B Boys? I know they have a lot of stores.