Your body builds up a resistance to capsaicin (the hot part). What may seem hot or ruined to some people is just comfortably warm to others.
There is a difference between Chili Powder and Powdered Chilies. Chili Powder is a mix of dried chilies, cumin, garlic and other spices. Powdered or Ground Chilies are purely that. The hotter the Chilies used, the more heat. I usually have 3 in the cupboard. A hot red that is ground Chilies. A medium green, also ground Chilies. (Better for pork and some chicken dishes) And a true Chili Powder that is medium heat but adds better flavor. When I am making it for myself, I add extra heat.
As for New Mexico, love me some Hatch peppers. I am not racist toward my Chilies. Red or Green, I love them all....oddly though, bell peppers do not agree with me. They smell and taste fine, but reverb for days.