Aye GBK is terrible like. Don't rate it at all.Of course but it's just a term generally used for burger places that cook the burgers fresh and let you decide how you want it cooked. I don't think anyones claiming the people who make them are Michelin standard chefs.
Most of them don't even label themselves 'gourmet' with the exception of GBK (which ironically is one of the worst out there)... it's just a loose term people now use for 'better quality than fast food burgers'.