Exactly and the same applies to any other source of food. Same reason it is okay to kill an <insert food source> and eat it. Eating is not a moral argument, its what we call a cycle of dependence. Every living thing lives off each other - you have to kill to eat. Noting you eat is non-living to begin with and the process of food production itself is fatal to other organisms which are not eaten. You can become a Jain and eat only fruits and vegetables excluding those that grow underground, a Jew/Muslim and follow religious dietary laws [or not], a Hindu and abstain from beef [or not]. All food taboos are due to philosophical reasons or ideological conditioning, but in and of itself, all food sources are equivalent and should receive yes, equal consideration as food sources. You may defend a cow as vigorously as a Jain defends a potato tuber but those are your PERSONAL reasons for eating or not eating some foods. To a Jain it is as unethical to eat a tuber as it is to eat a cow. If thats how you feel, you're welcome to go that route but to other people potato = food and cow = food.