Why are catholic priests not allowed to marry?

The reason why Catholic priest are not allowed to marry because they need to be devoted to the Lord, giving their full focus and attention to him. It has been said in the bible which is from Paul that being single makes the person focus his attention to the Lord for his attention are not shared or undivided by others. And another reason of this cause is because they are vowed to serve on the Lord, meaning that their whole focus should be served on no one but Him.