This is what I have heard many times when I talked with my friends and other people about relationships: "when you love somebody you should accept everything about that person unconditionally". I know that everybody has their own weak points but accepting everything is too much. It was always really surprising for me to hear something like this.
If everything was perfect in this world then I would agree with this statement but unfortunately it is the opposite - our world is in dire straits condition. And who does it ? It is you and the people who you love - your parents, your partner, your children, your friends etc. Thus if you accept them unconditionally something is not right here. If you allow your loved ones to abuse and cause harm to others then you are equally responsible for it. You don't have to do it yourself. It is enough that you don't act to stop it if you can.
Apart from this it is very common that the person saying the words that we should accept unconditionally our loved ones and all what they do, has a hidden interest within it. This person knows and is aware that he is abusing and harming others himself but - for own egoistic reasons and benefits - he doesn't want to change it and to hide this, he is using beautiful words to cover it up. In this case he accepts others the way there are in the name of unconditional love ( even though they are abusing others ) because this way he wants to be accepted by others and continue with his abuse and at least don't feel so bad about it.
Now... it is interesting to see what will happen if somebody ( e.g. the loved one ) doesn't share this belief about accepting him unconditionally and this somebody points out his weak points and "insists" on changing it. If your loved one doesn't want to open his eyes and make the change, then you will most probably become their enemy number one. And it is very common that he will try to bring to the surface all of your weak points, will make new ones, he will blame you and accuse you for all the problems in your relationship ( between parents, partners, friends ) and more. It is all to put you below and to make themselves superior to you so that he may continue with the abuse. If you are less than them, then your words are not valid, not important, not significant, not worthy etc. This is his ego in action in self defense. It tries to validate himself through invalidation of others.