Yeah we spent some time at Lake Atitlan and Antigua and found them equally inundated with gringos and people who had surely altered the culture of the areas. We were mostly living up in Flores which we found to be more Guatemalan but even there they have western influences. The worst is when the prices are inflated to the point that the locals can’t frequent the establishments. I hate that. If your going to ‘benefit’ a place, at least make it accessible to the locals who have been cultivating the land that you stand on.