Why do farmers say that about horses?

I live in a farming community, and take horse lessons. My instructor told me that any farmer will say "horses are useless, and hay burners. They are good for nothing." What is their perspective on horses when they say that? And then the next week there is this farmer's daughter on my bus that was eavesdropping on my conversation with my friend, me talking about horses, and she said "horses are hay burners, good for nothing." That made me so mad! I didn't want to believe my instructor, but it was true. I love horses with all my heart, hearing that just about broke it. Why do farmers say that? I mean the farmers that are against horses, and the farmers that do not have horses. The farms around my ares are dairy farms, mostly only have cows, and cornfields.