Hairy vetch isn’t bad for farmers, it depends on what your goals are and how you manage it. I like to use it as a companion with clover and rye or oats to make a mulch for no till vegetables and corn but to wheat and strawberry farmers it’s a weed that needs to be eliminated as to your larger point i don’t manage my food plots as intensely as cash crops but do give them a fighting chance, a few weeds don’t upset me unless it’s pigweed. I’m beginning to believe cover is more important for me to others food may be more important.