Why does my wife have this attitude toward my efforts?

I love my wife and we've been happy for a long time together. It bothers me that I give her credit for what she does in the house or cooking and thank her, but she does not like to give me credit for what I do. For example, I grill at least once a week for the family, including her mother and grandfather. I rarely get thanks for this. When I asked about it today, my wife informed me that grilling is just "heating up something and giving it a little charcoal flavor." I disagree with this, I think like any other method of cooking, grilling involves skill, timing, patience and so on. Add to that the fact that where we live it is routinely hitting 105-110 degrees outside and standing next to a hot, smoking grill for an hour or more is even more of a labor of love. Her family's method of grilling was always start the fire and immediately start cooking, char the outside of the steak or burger and then pull it out of the fire and eat it. This resulted in charred meat that was cold and often raw in the middle. Her father had no idea how to grill, and during our engagement we would routinely leave her family's house after BBQ and head to McDonald's. But my grilling is careful and done to perfection, just the right amount of pink left in the center, and well heated throughout over a bed of glowing coals that I built with painstaking care. Why does she have this attitude to what I do? What is my best response?