Shoule you be vegetarian?

Argument presented in prose

Do you think your local butcher will reduce the amount of meat she orders from the slaughterhouse if you become a vegetarian? Of course not! The supply chain for meat just isn’t sensitive to the quantities that a single person consumes. So by becoming a vegetarian, you'll never save a single animal’s life! But by becoming a vegetarian you’ll deprive yourself of the pleasure of eating meat, and you should only do that if the benefits would outweigh the losses. So you should only become a vegetarian if doing so would save some animals’ lives.

Model visualization

Can you figure out what's wrong with this argument?