well this is a strange post and maybe one may want to reflect upon their thoughts.
If you love someone one cannot change the behavior of anyone else but themselves.
You are right someone may find life difficult if they constantly are complaining about others.
This person has to look at themselves and find happiness for their self and no one ever can bring you happiness that is your job.
Try being on the other side of this senerio, if a person hurt you all the time with no regards to how it affected you would you stay???
Please have a heart and know that life is full of love and laughter.