None so deaf

There are none so deaf as those who will not hear, nor blind that will not see. No matter how much you want to help people with their problems, there comes a time when you finally realise that the complaining and lack of motivation is part of the victim mentality and is the security blanket - without something being wrong, they have no other conversation that will draw the focus to them. Eventually even good friends will drift away, seeking more congenial company, or less needy friends.
This shouldn't make us feel guilty in any way, as everyone has their own journey in life, and it is not our responsibility to ensure that everyone we come across is helped along the way, just as we cannot always expect our problems to be solved by others. We all grow (not just physically!) as we mature, have all made mistakes and learned from them, some quicker than others, and many of us have had light bulb moments when the meaning of life becomes a little clearer, but there is no way of making anyone else see things from our perspective.
To walk away is not to have given up, either on them or yourself. It is to have grown a little wiser with the allotment of time.