Believe me you dodged a fucking bullet. If they have an issue with your rented out restaurant selling non veg food, imagine the amount of grief they will give u and your family later on for trivial stuff.

Also, I am kinda glad they didn't listen to you even after you pleaded with them. He could have used your feelings for his daughter to blackmail you into doing things the way he wanted. He would always threaten you with "ending the engagement / marriage" everytime he saw something he didn't like.

Lastly, if the girl didn't plead to her father the same way you did, buddy, you deserve someone who would fight for your the relationship equally hard as you.