However, subjective morals would allow for rape, paedophilia and racism being justifiable to some, therefore we obviously have some tacitly agreed moral structure of society. The structure is also viewed, in some way, as "right", even if we accept it may change, so in that way it is reasonable to talk about there being a "right" moral.
Now if we think individualistically we can see differing morals (such as eating/not eating morals), yet to have defined morals you must again believe your own to be somewhat more "right" than someone else's morals.
Personally, the lack of a necessity for eating meat means that I chose to be vegan. Anyone who can see that there is suffering in meat farming and argue that they eat meat just for taste reasons is a weak and selfish person in my view. It's even worse when carnists "love" a pet!